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.