If I play a 720p title, and use an AVR to up-scale to 1080p and send across HDMI to a LCD display, what kind of latency will that introduce?

I'm especially interested in any experience you might have with the Sony STR-DA5200ES, the Pioneer Elite VSX-84TXSi and the Yamaha RX-V2700, so if you have one of these with this set-up, I'd be very interested in hearing about it!

Mumble mumble.

Is nobody running their console through an A/V receiver? I'd really like to keep all the mess in a cage, and run a single HDMI to the screen, but if there's too much lag, that won't work.

I'm running my PS2, Xbox, PS3 and Wii over HDMI to my HDTV through a Pioneer elite 72txv... The 72txv does not upscale the signals it just passes them along so I'm "assuming" the lag is not too bad... My old HLR sammy is sooo laggy that I'm focused on replacing that first before I start looking to see if the reciever is introducing a problem as well... Sorry I can't be of any real help, but I'm interested to hear what people are experiencing as I will most likely be upgrading my reciever after replacing my HLR.

Yeah, most pass-through scenarios are not laggy, although then you get the upscaling lag in the TV instead (as you noticed).

Of course, if you're getting analog in, and putting digital out, then there's at least a sampling stage of some sort, that might introduce a field's worth of lag. That I can live with, though. It's when lag is more than a frame that problems ensue.