The Omni is having a Mediterranean New Year Party with Belly Dancers...could be a cool thing with the right date...although I don't see reserved seating, I do see that they have limited VIP seating which is probably better than vanilla reserved seating.
http://events.austin360.com/austin-t...ty-austin-2012
If you are looking for something outside of downtown, then Vivo Lake Creek on 620 is having a New Years Eve Masquerade party which does have reserved seating...and once again, being a Masquerade party...would be pretty fun with the right date.
http://www.austintexas.org/now_playi...detail?id=3466
Most nice hotels have pretty good New Year parties...so always a good idea to check out places like the Four Seasons and the Driskill.