Initially, cellular on the Watch was a non-starter for me. (Apple didn't say 'LTE' though.) I doubt I'll ever find myself on a paddle board and need to make or take a phone call. Sure, it could happen.
But having a fully-functional GPS on the Watch has it's appeal, especially since I can pair it to my motorcycle helmet headset. So I got Keynote Fever® and am considering getting a 42mm Silver Al Cellular S3.
I'm still not sold on the monthly charge, supposedly $10/mo at att. There also the issue of the electronic SIM. If I leave att (phone is already unlocked) how easy is it to take the Watch with me? Will it have to be unlocked or is it considered unlocked from the jump.
I'm tempted to pre-order and then try getting one at a Store.
Just checked Apple's site and the S3 does have LTE.