I’m not sure how trustworthy the source is, but a PalmInfoCenter.com reader wrote in with some details they found out while at a local Sprint Store about the Treo 700p -

“So the story is our source visited a Sprint store this past Saturday. He asked their lead tech if he knew anything about the release of the Treo 700p. The tech pulled up a webpage from Sprint that not only had the Sprint part number for the 700p but also had a “May/June” release date indicated, which he let him see for himself.”

PalmInfoCenter | Treo 700p Spotted, Likely May/June Release