As xfloggingkylex said... excellent value for the money. IMO excellent design and control features, well built, seals helps protect the body from the elements, takes a battery grip, the shake reduction doesn't work miracles but does work pretty well with all lenses.
As for image quality...
ISO only goes up to 1600, and at 1600 is noisier than some of the alternatives. Nothing terrible if you expose properly, but could be better (which is why I still use the 6mp k100d which has better noise control at 1600, and has ISO 3200).
But, otherwise excellent, with potential for very high resolution (apparently slightly higher than the competition using the same sensor).
Now for the Pentax system overall...
There's a flash system, which works well. The lenses available are all very good. There are definitely less to choose from than Nikon or Canon. However I would say most needs are now covered in wide and normal focal lengths, with some unique offerings like the "Limited" pancake lenses. But the current range is lacking telephotos longer than 200mm, so for now you would have to look to third parties or use the older compatible ones. This IMO is a temporary situation, and one which should be resolved soon as Pentax are due to release new teles (zooms and primes) before long. In other words the system is not perfect, but it should cover most needs, and what it does it does well.
In other words I'd be happy to recommend the K10d. Especially now as the price is continuing to drop, and it represents very good value indeed. But I don't know whether I'd recommend it to you, as opposed to any Canon, Nikon, Olympus or anything else... because obviously that has to be down to you and your own priorities.