He'll likely have three bites at the SCOTUS apple:
O'Connor
Rhenquist
JP Stevens (84 or 85 years young!)
Now that individual accounts for Soc Sec are likely to fail, the War on Militant Islam & his SCOTUS appts are likely to be his legacy. If he screws the appts up*, the Republicans can kiss their ruling majorities goodbye.
* Screw Up - Appoints some milquetoast, weasely "moderate" who'll drift left...like O'Connor, Ginsburg, etc.