I think that the 300, 500 and 7900 series phones are supported for the UC 500 series, but what about some of the other models?
Good Afternoon,
Don't forget the 6900 series phones
What about the 8900 and 9900 Series?
Down the road, looks like later this year maybe
No firm commitment date as of yet
This page on the support forum, https://supportforums.cisco.com/docs/DOC-9827 , is a great resource for questions like yours. It lists the phones and supported firmware versions for each release of the UC500 software.