For what it is worth, my two cents
After umming and ahhing for months and whinging about the things that annoyed me about my K10D I finally bit the bullet and got a K5....LOVE IT!!!
I am not saying I am a flash photographer and the K5 is probably well above what I will need for a while but given the things that annoyed me about the K10 (slow AF, burst speed and weight to name a few) I am ecstatic with my upgrade, especially after photographing the cycling on the weekend with my husband using my old camera and whinging about all the things I did!!
So I just want to say that if you are where I was a couple of months ago trying to decide if it is worth it, I am so glad I upgraded, just in case it helps anyone else to decide!