Right now it works with 3.5 except for the new WYSIWYG input box, which we are working on and will have an update for shortly. I expect an RC3 anytime, so we're keeping an eye out for it.
We have many people running 3.5 with the current release of PhotoPost which has most all of the 3.5 code necessary to run with WYSIWYG box turned off.
Please do not PM me for support or sales questions. Thank you for your understanding.