Can I install TextMate 2 and keep TextMate 1? I would like to try TextMate's new version but since it is a beta release with some bugs and unfinished features, I don't want to use it everyday. Is there any way to install TextMate 2 and keep Textmate 1?
No need to use /Applications or ~/Applications, you can put text mate 2 in any folder you wish. 

For example if you have Textmate in /Applications/Textmate.app, create a folder in /Applications/TM2/Textmate2.app