Stuck at Mojang screen

I opened up mc yesterday using a standard minecraft.jar (1.4.7 I think),After I loged into the mc window it asked me to update after I updated I got stuck at the mojang logo/white page. Rather I reset it or my mac or try to re-force update I can't get past that point. I've tried playing in the browser and I cant even get that to work either. Any advice would be helpfully all I wanna do is just play that sweet 1.5 you guys put out!

Thanks for all your help and a amazing game
Thank you again,
urenhazard