No, an optical drive draws far more power than the ~2.5W a USB port provides. It'll need external power.
They're flat-out denying they even have plans to release one. That's typically beyond the veiled coyness of a company not wanting to tip off customers too soon of upcoming and improved products.
I don't see why you have to mix PS3 into this discussion, it's completely irrelevant (and please note that "console vs. console" posts are heavily frowned upon by the moderators), but to briefly touch upon the subject you bring up, one has to consider PS3 games will always come on BR media. 360 games will
never come on HDDVD media. Wether one approves on a fundamental level of Sony's decision to include BR or not, one still has to agree that with this in mind, BR belongs more as standard in PS3 than HDDVD does in 360.
Besides, I find it a little bit amusing you're disagreeing with BR in PS3, yet get fairly agitated when people question the probability of HDDVD appearing in 360.