It's on the GameFAQs website. Just search for "WWE SmackDown vs. RAW 2011" under the list of PSP games, and click on the "saves" tab, and voila, instant updated roster.
However...there is an even better setup than that: Sultan Mitu's WWE 2K14 mod. Yes, it has its bugs (some models don't have AI or are missing some AI routines, and you can't use the Elimination Chamber in any match type), but overall, it's a pretty decent mod.
An even better one than that is CrocoX111's WWE '13 mod. Go to his Facebook page to get the links. Trust me...you will NOT be disappointed! The roster is HUGE--it's around 80 wrestlers (IIRC). Additional features include hacked theme songs, entrance videos and custom moves not originally included in the default SvR '11 iso. One final thing: this mod even has D-THROWS!*
*To D-throw almost any standing grapple move, just rotate the analog nub while the move animation is being performed. Use this to help avoid unwanted rope breaks (if you wish to have them active).