I always have CBA when it comes to Pentax - I wanted a white Kx but it's the only one I've wanted that I didn't buy. Now I'm trying to decide whether I want a white Kr more than the K5. Since I'm not anywhere close to being able to buy, I'm not in a hurry to decide.
Do I NEED another camera? Absolutely not. For the most part I don't find the K7 that limiting - only when shooting at higher ISOs (like I did when shooting surfers a couple of weeks ago). I would love to have the K5 in that situation! But since I don't shoot surfing or sports of any sort very often, I can live without it.
Did I NEED to buy the FA 77 Ltd, when I already had the DA*50-135? No. But after trying to talk myself out of that lens for over a year, I bought it. And I have no regrets at all.
In fact, I really don't NEED any digital camera or lens. I don't make a living (or even spare money) from my photos. But it's my hobby and the pleasure I get from it is absolutely priceless. When I can, I'll buy either the Kr or K5, just to add the high-ISO capabilities, I do occasionally find the K7 frustrating on that score.
So I don't discount WANT as a very big incentive/reason for getting something. In some cases, it's a lot more important than NEED. And the two new cameras will expand your ability to grow as a photographer, giving you so much more satisfying results when used indoors (I know, I used to own the K10). So really you can justify getting one of the new cameras as need-based as well as want-based.