The info was good, the testing was meh. Audioholics.com's tests are far more comprehensive scientific and objective wise.
Your take-away from all this should be the following:
At lengths less than 4 meters you can just about use silly string (OK, not really) and get HDMI to pass at any current resolution. At less than 3 meters you'll even extend that to 12-bit color and possibly the next crazy idea HDMI Licensing decides to throw at consumers. Don't spend a lot on these cables and if you want to save money you won't let anyone at a big box store talk you into buying from them.
At long lengths (over 10 meters) you really need to pay attention to the manufacturer if you don't want to risk running into potential problems with 1080p and future formats such as Deep Color. With that said, just about any cable at or under 10 meters will pass 720p/1080i and nearly everyone will pass 1080p at 8-bit color as well.
If you have an existing HDMI cable and are running into problems, we'd suggest at least attempting the insertion of an active component at the sink (display) side. This is going to be far cheaper than ripping out your walls and re-running new cables - and likely just as effective.
HDMI has proven to be a moving target and there is no telling what crazy (likely unnecessary) format they will try to push down the cable next. Due to this, it's always good to "overbuild" your cable install, especially if it's a longer distance and going to end up behind drywall.
If you're not prone to upgraditis and think 1080p will be your maximum resolution for the life of your install, don't sweat it...
The fellas at Audioholics don't like the HDMI standard in general mainly because it's a 'sidegrade' from DVI as opposed to a real upgrade.
The first page explains very well how HDMI works:
More complicated than you think:
Edited by chinesekiwi - 2/16/11 at 3:31pm