I've been running the final leaked version of JB. Many of us had the same problem with battery life. The issue was Samsung Push. I don't use it myself, so I disabled it in Settings - Applications - All. You can also use Titanium Backup if you are rooted.
I have not yet installed the Sprint OTA - waiting to ensure that I don't lose root - so I can't say for sure whether this issue was resolved by Sprint... so YMMV.
Palm Pilot-> Palm Pilot 1MG upgrade-> Palm IIIx-> Visor Deluxe-> Visor Prism-> Clie N610c-> Verizon Kyocera 7135-> Verizon Treo 600-> Sprint Treo 650-> Sprint Treo 700p -> Sprint Touch -> Sprint Diamond-> Sprint Hero ->Sprint EVO -> Sprint Photon -> Sprint Samsung Galaxy III