Hi everyone - I work at BJC, and thought I'd chime in a little bit on this...
One of the big issues that isn't mentioned is that not all HDMI output and receiving circuits are created equal. During our testing of the BJC Series-1 cable, we found that one set up would work perfectly at 50 feet (1080p), and then we'd change only the output device and find that no "handshake" was happening. I take phone calls all the time from people running into this issue (changing one device, and then nothing works). Some units are notorious for having weak outputs - many of them are cable & satellite boxes. Less than 1% of the cables returned to us as "bad" are actually faulty. Many times, boosters, or shortening the run is the only fix.
To be honest, we have many customers running 1080p at 100' (our longest HDMI cable). While this will not work with 100% of the gear out there, chances are it'll be fine on most of it.
One note on the whole Cat1 & Cat 2 HDMI certification - bear in mind that those numbers don't really mean a whole lot when it comes to performance. There's no way in hell that a 100' HDMI cable will pass even the Cat 1 eye pattern test, but it still functions well on most devices. As far as the new 3D HDTV units on the market - many think that they'll need a new cable. This is false - but don't just listen to me... there are several other independent articles that cover this:
blogs.consumerreports.org/electronics/2010/03/3d-tv-hdmi-41-cables-sales-not-necessary-regular-basic-hdmi-tv-bluray-player.html
consumerist.com/2010/03/sorry-monster-you-dont-need-hdmi-14-cables-for-3d-tv.html
Also - beware of any seller calling their HDMI cables "v1.4". This is in direct violation of the licensing agreement with the HDMI licensing organization.
Cheers!