I guess I just became accustomed to checking the time like that on the 650. Two places I can think of off-hand where it's useful are at the beach and reading on the toilet
(don't tell me you don't do it!)
Probably a simple enough feature for Sony to add in a firmware update, however I doubt they think of it as a 'feature' per say on the 650...just something us users have discovered that the software designer stuck in that particular spot on a whim. I don't believe it's in the manual anywhere for the 650.
I like the comment about 'books' not having the time on every page.
That being said, most every other device we carry around, from cell/smart phones to ipads, all display the time plainly enough - reducing the need to wear a wrist watch or carry a pocket watch-on-chain anylonger!
At any rate, we've all set up the date/time on the T1; it would be nice to be able to check it more easily if so desired!