I've been stubbornly avoiding replacing my 10 yr old Sony receiver but it looks like its time has come. I realize that I have very little idea what is important feature-wise these days. I'd like something that supports video and audio input/output, preferably digital, and allows me flexibility around the new alphabet soup of HD tv.

Any recommendations or features that I should consider? Price range is $500-700 US. I'll consider anything except Sony.