Palm just posted an update on their developer blog telling developers—all of whom are anxious to make apps for the Pre and start making money—that the SDK won't be out until late summer.
On the one hand, it's good news that they're going to get an SDK available in three or four months from launch. The iPhone took an entire year to get an SDK available. The bad news is you have to wait three or four months to get Palm Pre apps that aren't from people with closer relationships to Palm.
But, they're going to "accelerate" their early access program, letting in more developers into their inner circle. That's good news, since it means an increasing amount of apps between now and the general release of the SDK. [Palm blog]