While Tali may have been blessed the suitable "curves" by the people at Bioware, I would urge the "Talimancers" (sounds like a follow up to Neuromancer if you ask me) to reserve any judgement, if you can call it that, until they happen to see an actual Quarian face, sans helmet. Given that there is probably as much chance of that happening as there is the chance of Master Chief removing his helmet and revealing himself to be the illegitimate child of Gordon Freeman and a female clone of Solid Snake, I guess they're just going to have to sit tight.
As was highlighted by King Teabag above, having seen glimpes of the upper part of Talis face in ME1, I've always figured there's something alien about the quarians to a degree that they probably wouldn't really be attractive to humans (at least until the inevitable quarian fetishists start cropping up). I've still though Tali to be a nice character, but more in a rather naive and innocent way...as has been said, she definitely seems more like a child than anything else.
Best they just leave the romance and sex scenes to Subject Zero and the like (along with Samara no doubt).
