Alright, so I got the collectors edition of oblivion and I am questioning weather or not to start playing...the problem is I'm leaving in 4 days (for 2 weeks) and wondering if I will have time to finish this game. Thing is It took me 2 weeks to finish the Fallout storyline because I would keep getting distracted and did almost every side mission...does Oblivion have the same side quest and loot system as fallout 3? I don't want to start and then have to finish the game 3 weeks later because I fear losing intrest...

You will not finish this game in 4 days. You might finish the main quest line, but that's about 3% of the appeal of the game.
It is much like Fallout 3 in the way that the actual fun lies in exploring and doing funky sidequests getting unique loot, but even more so for Oblivion.
 
Take your time with her, don't rush the experience.

The main quest is actually pretty terrible. Better to just skip it and go adventuring.

" You will not finish this game in 4 days. You might finish the main quest line, but that's about 3% of the appeal of the game. It is much like Fallout 3 in the way that the actual fun lies in exploring and doing funky sidequests getting unique loot, but even more so for Oblivion.  Take your time with her, don't rush the experience. "