Is there any chance that the 1057's firmware will be updated so it can process MPCM through HDMI? Or is it already capable of doing so?
It never will and software can't fix that. The 1057 is a 1056 with a passthrough HDMI board slapped into it.
Maybe I'm just ignorant when it comes to the workings of mid and hi-fi companies, but why does a company like Rotel seem so behind when it comes to integrating sensible features such as MPCM? HDMI ports that can only switch video? So what?
I guess what really annoys me is that they don't seem to release things too often, and their next product seems to focus on video processing more than anything, with MPCM being an uncertainty. It can't be that difficult to implement.
It's not that it's too difficult to implement. Manufacturers of mid- and hi-fi are MUCH smaller companies than big dogs like Denon, Pioneer and Yamaha are, with far fewer engineers. This means that they usually get their hands on new chips (like the ones that would enable full-blown HDMI 1.3) long after these larger companies do. And when they finally do, the products have to go through rigorous testing before they are ready to be mass-produced - all with less manpower. With time, they're bound to have a reliable product that has all the "critical" gadgets you get with mass-market Japanese receivers that receive face lifts every year.
Rotel isn't the only company this happens to.
I can't get a straight answer from Rotel (mostly because they really don't know for sure yet) whether the RSX-1058 will support LPCM audio over HDMI, but they seem to be leaning on no. Hopefully, they will be able to offer this incresingly important feature on the '1058 because frankly, $700 extra is a lot to pay just to get video scaling. At $1,999, you're a couple hundred dollars shy of the RSX-1067, which has a much better amp section.
What I do know is that the '1058 is not intended to replace the '1057 completely and that the two models will coincide.