First off, I don't get it when I see the Dark Mark on Draco before he's seventeen. Buh? Why would Voldemort want a member of his elite inner circle who is 1. Not even fully educated and 2. Not allowed to perform magic outside Hogwarts?
I mean, fine, the "not fully educated" bit can be explained by saying that Draco has studied the Dark Arts on his own time and is very good at them (of which there's no actual canon evidence, but there's nothing in canon that contradicts this, either). However, I don't see how the underage wizard thing can be overcome. Of course, it's possible that the Ministry don't actually watch underage wizards. It's confusing in canon because Harry is blamed for Dobby's Levitation Charm; they might just watch areas where underage wizards are living for instances of magic, but that would be difficult in wizarding households where other family members are allowed to do magic.
At any rate, all of that is largely irrelevant because of the Dark Mark's only function that we've seen (it may not be the only function of the Dark Mark, but it's the only one that's continually referred to). When Voldemort uses whatever magic is tied to the Dark Mark, his followers are expected to Apparate to his side. Draco can't Apparate until he is seventeen and in possesion of a licence to Apparate. So it makes zero sense for Voldemort to put the Dark Mark on him -- he can't use it.
There's obviously the whole "Voldemort wants to use Draco/any other Death Eater's kid to spy on Harry" but he doesn't have to make him a Death Eater for that. I'm pretty sure that Draco would be more than happy to spy on Harry for Voldemort without an ugly Dark Mark on his left forearm.
However, that's Voldemort. What about Draco himself? Let's say he's seventeen, let's say he's done with school and the war is still going on. Would Draco want to be a Death Eater? Usually when I ask myself that question, my impulse is to say, well, no. Various reasons, including but not limited to the following.
He's a coward at heart, and Death Eater-ing is presumably dangerous. The Death Eaters swear allegiance to Volders and they seem pretty gung-ho about service to the Dark Lord (Leave Nott, leave him, I say!). I'm not sure I can see Draco wanting to actively go into situations in which he is risking his skin.
For all his supposed well-versed-ness in the Dark Arts, he appears to have led a sheltered life as he doesn't seem to be as affected by the Dementors as, oh, let's say Harry. We know for a fact that Draco has never seen death - he couldn't see Thestrals in OotP. This makes me think that Lucius and Narcissa have tried to keep Draco from being exposed to the nastier aspects of life. I mean, it can't be a very unhappy child who can't identify with the experience a Dementor causes, can it? Even Dudley (to whom Draco is most frequently compared) is affected by Dementors in a way that makes him pass out, but from Fred and George's account of Draco's behaviour during the Dementor inspection of the train, he's scared of the Dementors themselves, rather than affected by them in any way that's, well, lasting. He takes particular gleeful pride in being able to walk past the Dementors guarding the castle in PoA (juxtaposing it with Harry's fear of the Dementors), which makes me think that they don't make him feel all that awful. So, he's sheltered, despite his apparent fascination with the Dark Arts (in Borgin and Burkes and his comments regarding Durmstrang) - perhaps his fascination comes from the fact that he is unable to fully comprehend just how horrible some aspects of the Dark Arts are.
I don't see Draco wanting to participate in any activities where he stands to lose his life. It could be argued that he has a measure of courage because he plays Quidditch, and that would be a fair argument. Except it seems that as any teenagers, both Draco and Harry seem oblivious to the fact that a sport played on flying broomsticks can be hazardous to their health; I think it's common amongst teenagers to think they're invincible and surely nothing can harm them. However, the point stands. I don't think Draco lacks courage altogether but he's certainly not a brave boy. So for Draco to go and become a soldier (even if it's an elite division) in a war seems a bit of a stretch for me.
However, there's Lucius and Draco's apparent adoration for him. Yes, I can see Draco becoming a Death Eater in order to make Lucius happy. But would Lucius want his only son and heir to put himself at such a risk? I've seen various characterisations of Lucius, and some allow for it while others don't, but it can really go either way at this point.
Also, there's the whole issue of Slytherins being pretty much the outcasts at Hogwarts, at least the sentiment seems to be that people don't trust Slytherins and stay away from them. When Harry and Ron are disguised as Slytherins and tell a Ravenclaw girl (Penelope?) that they've forgotten the way to their common room, she snubs them; at least that's how I've always read that scene. Excuse me? I'm a Ravenclaw! (Subtext: Not a stinky Slytherin like you, thanks.) Once the war starts in earnest, clearer lines will be drawn and perhaps Draco (as well as other Slytherins) will want to join the Death Eaters (once they're old enough, etc) just to have somewhere to belong. That actually seems like a more plausible possibility than "Death-Eater!Draco due to Lucius".
Finally, and maybe most importantly, do we know if Draco's picked a side in the war? I don't think we do -- all indications seem to be that he certainly sympathises with Voldemort's side, but has he firmly planted himself on either side? In GoF, he's convinced that Harry's side is the "losing side" but will he think so after OotP, when his powerful (whom Draco clearly worships for his influence) father has been thrown in jail by the "losing side"? In canon, he's likely to grow even more polarised towards the Dark side, especially considering that OotP marked the first time that Draco and his goons actually tried to attack Harry. There's always personal growth, however, and there's always something that could happen to make Draco change his mind about which side is really "losing" -- because I think that ultimately, what matters to Draco is to be on the winning side. I'm not a fan of redeemed!Draco but the opportunity for redemption is certainly there. I just don't believe that Draco would ever take it.
And a bit of randomness to make imadra_blue paranoid.
The Killers are love. Their rhythms make me think dirty, dirty things. About Hufflepuffs, mostly, but that's another story. *cough*