bike died earlier in day - waited a few hours and it started - let it idle a few minutes and it died during idle.

Jumped my bike from my brothers bike and it started - was waiting a minute or so before taking off and the bike got really weird - misfired and popped and then died....WTF?

Last couple of days I've been having trouble with the battery keeping a charge so was going to take it in but now it seems pretty serious!

Any thoughts?

 

Not serious at all, new battery and have your charging system checked. Batteries take a dive from time to time for no apparent reason and the symptoms you describe are pretty typical, at least in my experiences anyways.