Ubuntu 10.04 server supported til 2015 (May, I think). That's not too far down the road. Since one has to upgrade PHP and MySQL to get to 'long term supported' version of Moodle 2.7 may as well do it all at this point and avoid the pain of being forced to soon. Besides that, 2.3's are now under 'legacy versions - no longer supported'. Any issues with 2.3 and newer versions of PHP/MySQL ... well, if there are probably only depreciated warnings (but that depends on what one has done with 2.3.x - customized it much?). One thing for sure ... if there are issues, don't think it will be fixed.
While at it, might check into the package you have with GoDaddy ... how much memory, how much HD space, how many cores, etc.
So onwards and upwards might be your best strategy at this point. Best be proactive rather than reactive ... or so I've heard!
'spirit of sharing', Ken