I've used a lot of Canon's compact cameras, both IXUS/Elph, A-series and pre-IXUS/ELPH S-series, and they're about as good as you can get in that form factor.

That's a backhanded way of saying that high-ISO performance, which you'll be needing for those low-light party shots, is much better on cameras with the larger lens, larger sensor, and higher processing power of a DSLR. You can do it with the IXUS, but you may find yourself wanting to invest in Imagenomic's Noiseware plug-in for Photoshop.