Well, I have finally decided to make the leap to HD without MPEG-4 for the time being and here is why:
I had held off till HD-TiVo came out and I was waiting for the price to drop a bit and any potential bugs ot be resolved. Then, because MPEG-4 would make it obsolete in a short time, I decided to wait even longer for the MPEG-4 DVR. But, now I'm tired of waiting.
The only thing MPEG-4 adds right now is locals for the 4 big networks. Since I am in the NY area, I could already get those HD channels in MPEG-2 (and I expect this to continue to be the case for some time). Sure, PBS will be added soon, but that's not enough to make a difference to me. I can get the locals with an OTA antenna, so locals isn't a big enough issue for me. (I installed the OTA antenna Monday and it works great!)
Let's face it, no matter what rumors are out there, it will likely be 12 - 24 mnths before we can realistically expect significant national HD programming additions.
The R15 is a dissapointment...a major step backwards. Not that I am unwilling to give it time, but right now my experience is that it is inferior to TiVo. I expect that the new HD DVR will have similar issues that will have to be resolved over time. Furthermore, I expect, prices will decline on those units from what they are initially sold at.
HR10-250 prices have dropped considerably. So, I concluded the best move for me is to jump in and buy one now and put off any move to MPEG-4 till there is a real benefit to me to upgrade.