If you are going to go higher than 44.1, don't bother tracking at 48 because there is going to be little difference in the frequency response and, if anything, your audio is going to be compromised when you do bounce it down to 44.1 for mastering.
If you really want to record at a higher sample rate, try 88.2. Even then, you aren't going to notice much ov a difference and its going to take up twice as much room on your hard drive.
The only reason a sample rate ov 48 was ever popular is because there was a time when people were still tracking with A.D.A.T. and other digital 8-tracks whose host format was 48.
I'd recommend getting a book by Bob Katz called "Mastering Audio" or something to that effect.
Here is the book I'm referring to, its a wealth ov valuable information on digital audio:
http://books.google.com/books?id=EBC...with-thumbnail