Yes do it, but things you need to consider
1. Do i have enough ram?
2. How am i going to back up the unit incase something happens?
Sure the standard mbp has enough ram, but the more you put in it, the better the unit will run. As for backing up the hdd, i would suggest a external drive, which must be bigger then what you have in the laptop now. Use carbon cloner to copy the entire drive over to the external one.
Once that is finished, you can then boot of the drive to see if the clone was sucessfull. Then boot of the os x cd, and do a archive and install. That way it will move the tiger installation to another folder and install leopard whilst keeping all your settings intact.