One of the major holes in Federer's impressive resume is the record for most weeks at #1. He needs just two more weeks at the top to break Sampras's record.
Typically, about 11,000 points is enough for #1 (yes, I realize Djokovic currently has more than that but almost by defition he would have fewer points if another player got to 11,000).
Federer has picked up 3000 points in just the past month (Basel, Paris, London). He would therefore need another 8000 points. Here's one possible roadmap for how he could regain the #1 spot by the time Basel 2012 rolls around:
One GS win: 2000 pts
One GS final: 1200 pts
One GS SF: 720 pts
One GS QF: 360 pts
ATP World Tour Masters 1000
One win: 1000 pts
Two finals: 1200 pts (600 each)
Two SF's: 720 pts (360 each)
Two QF's: 360 pts (180 each)
ATP 500's and 250's
One 500 win: 500 pts
One 500 final: 300 pts
One 250 win: 250 pts
One 250 final: 150 pts
That would give him 11,760 points. Seems doable, no? What do you think?
I think he will hold the number one briefly. He seems more motivated then usual and his main rivals are out of form and may like federer seen their best days already.
Plus like you said he is off to a best start.