As you can see from a side-by-side feature comparison, the K-5 has a few advantages — 14-bit processing, somewhat faster shutter, a few more modes on the dial. It has a top LCD screen, and it has a magnesium-alloy body. On the other hand, the K-30 has some improvements of its own. Whether these things are compelling to you is a personal decision, but as Digital Photography Review says in their hands-on-preview:

... we can't imagine Pentax expects to sell many K-5s once the K-30 reaches shop shelves.

The K-5 is basically over as a new model, and of course the speculation is rampant on what will replace it. Pentax will surely release something at the K-5's former over-$1000 price point *, and given how exciting the K-30 looks, that will be another hard decision all over again if you wait another few months. (Waiting for that is not my recommendation — my suggestion is to buy a camera and start using it, as the advantages of a real camera in the hand beat two fantasy cameras in the bush every time.)

You may want to consider a used K-5 — it's likely a lot of those will be coming on the market as the technology-generations dance plays out, and the close comparison with the low-priced K-30 will probably mean those are quite affordable. You might even go for a used K-7, which has most of the same features but an older (capable but more noisy) sensor, and spend your budget on lenses.

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* I'm leaving this as-is because it's inherently a point-in-time question, but for what it's worth, the K-3 replaces the K-5, and now the rumor mills are on to speculating about what might replace that. It's a never-ending game.