Currently Being ModeratedApr 25, 2012 5:19 AM (in response to littlekelli)
Another is watch
Currently Being ModeratedApr 25, 2012 5:24 AM (in response to littlekelli)
For what it is worth, every major (10.x) new upgrade in OS X since the public beta has allowed for a simple upgrade of your existing version (as long as the existing version was the most immediately preceeding version). So 10.2 allowed for a simple upgrade from 10.1, 10.3 allowed for a simple upgrade from 10.2, ..., right up to 10.7 allowing for an upgrade of one's existing 10.6 installation.
So, the odds say that yes, if you have Lion, you should be able to simple upgrade your existing Lion installion to Mnt. Lion without loosing anything. As with any system update/upgrade, as a brody mentions, you are strongly encouraged to backup everything before upgrading - any software or OS installation/update/upgrade can go awry.