It's a pretty interesting list, actually. Here's what comes to mind.

• DVI video switching
• component video switching, including cross-conversion from s-video and composite.
• more sophisticated digital bass management (four independently adjustable crossovers in place of the 1050's one adjustable crossover)
• bass management on 7.1 direct analog audio input (either an analog 80Hz crossover or the digital bass management)
• additional processing modes (DTS:ES, DTS NEO:6, Dolby EX, Dolby Pro Logic IIx)
• more digital inputs
• front AV input
• Audio sync delay

There are probably a couple other differences that I haven't listed. Some may mean nothing to you, of course, but that's a decent start.