Last night, during the wrap party, they mentioned that they're keeping the Paypal option open for a while longer. They listed some stretch goals for the additional funds:
550k - Translations (German, French, and I think Spanish, with Portuguese a possibility)
600k - Cluck Y'egger mini game (launched from the game menu)
625k - Cluck Y'egger animated graphic novel drawn by Mark Crowe.
650k - An additional level in the game featuring a playable female protagonist.
700k - EGA graphics mode
They didn't mention a specific deadline for paypal pledges or the stretch goals. Hoewver, a number of these can be added pretty late into the development, so I wouldn't expect them to cut Paypal funding until they need to lock down the game and finish it for release.
For Paypal pledges, now that the Kickstarter is over, those pledging will not receive any Kickstarter exclusive items like the Buckazoids. I think those paypal pledges that came in before the Kickstarter ended should get them though.
In addition, they're planning to open up a store for selling SpaceVenture merchandise. They previewed a Cluck Y'egger pilot wings pin that will be available. They also talked about the possibility of another Buckazoid coin with a different design from the Kickstarter exclusive. Purchases from the store will go towards the stretch goals.
Keep in mind that this is mostly from memory of what was said, and the Two Guys were pretty blitzed last night as well. So all this is subject to corrections or changes when they post the official announcements.