It wouldn't be the first time they've done a major update so soon. iOS3 only went to 3.1.3 before they went to iOS4. Supposedly iOS6 will be announced at WWDC which is still a ways out which means the firmware wouldn't be released for another 3 months or so. And even then, the chances that the 5.1 exploits pod2g has won't be patched are slim and none. If you remember last year at JailbreakCon, the Chronic Dev team announced they had 5 exploits for the unreleased iOS5. By the time iOS5 was officially released most of those exploits had been patched. I'm sure the same will happen this time around.
I really hope they don't wait.