Like RBennett, I'm not sure what "features" Golf4food is talking about.
The closest competitors feature-wise to the K20D are the 50D and the D300, I would say it's spec'ed somewhere between them. (It's certainly higher spec'ed than the D90 despite the D90 costing more!)
Both the D300 and 50D have faster FPS ratings and "common knowledge" is that they have faster autofocus, but anecdotal evidence has also shown that the Pentax might be more consistent. They also can both AF in Live View mode unlike the K20D but it is pretty slow. They do both have larger LCDs.
Neither of the C/N models do video, but the K20D has a 21fps "burst" mode that is pretty comparable to what you get from the D90's video mode (minus sound.)
The 50D has minimal weathersealing. The K20D has excellent weathersealing, certainly as good and maybe better than the D300. To the best of my knowledge, the 50D cannot control a wireless flash without added hardware, whereas the K20D and D300 can using the onboard flash.
Some K20D-exclusive features include the ability to tune the color of the LCD, the Hyperprogram mode (instant Av and Tv modes without touching the mode dial), the aforementioned burst mode, higher mp ratings than anything other than the 50D, dedicated buttons for bracketing (instant HDR!) and Raw, the ability to shoot in DNG mode, in-body RAW processing, built-in dust checking (no need to shoot a wall then adjust levels later), Sensitivity Priority mode, Shutter/Aperture Priority mode (select both and ISO adjusts as needed), and probably several others that I'm forgetting. IMHO, these are mostly features that are really useful for a photographer rather that just checkboxes in a feature list.
Then there's that whole image stabilization thing! These seems to be rarely mentioned in the C/N world but it's amazing to me that they still refuse to add it. The upshot is that you have pretty much no stabilized primes and very few stabilized third-party lenses. If you want a stabilized "standard zoom" (17-50mm or so), better be prepared to dig deep!
So, feature-wise, I think it's pretty solid compared to its competition. It's also older than the 50D and about six months newer than the D300. It also retailed at about $700 cheaper than the D300 and is currently $800 cheaper, and is $450 cheaper currently than the 50D. It's a screaming deal no matter how you slice it.
If you feel that you must have AF in liveview or faster FPS ratings or a .3" larger screen in order to get acceptable photos, then the K20D isn't for you. I would say that it's pretty much a given that the K20D replacement will have those features and almost certainly some form of video.