Dave Winer:

Unless Google also adds a disclaimer of all patents on all the new stuff, I'd be very careful about which ones we adopt.

The Google Data Protocol Patent License:

Subject to the terms and conditions of this License, Google hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this License) patent license for patents necessarily infringed by implementation (in whole or in part) of this specification. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the implementation of the specification constitutes direct or contributory patent infringement, then any patent licenses for the specification granted to You under this License shall terminate as of the date such litigation is filed.

I am not a lawyer, but I think that pretty much covers it. This bit of FUD slinging from Dave is particularly infuriating since I wrote that patent license.