I started noticing an interesting change in my email over the weekend but I thought it was just a fluke. I know RIM was supposed to add 2 way read/unread sync for Gmail this Spring but they have been really flakey about when that would actually go live. Reports have already told us that it has been on for a few weeks in the EMEA regions but from what I have been hearing from readers and friends along with confirmation from Michael at BGR it is now on for North America.
Let us know if it is working for you! I was surprised I did not have to remove and add my email accounts again to get it to work.