Congrats Tamim.
Let's look at the chance of him playing in the XI:
Other overseas in PW:
Callum Ferguson (AUS)-Middle order batsman so 50/50 to pick him or Tamim
Nathan McCullum: Lower order bat and handy with the ball...i guess no competition with Tamim
Angelo Mathews: Injured, even he his fit, he got to play for his country vs England
Wayne Parnell: Definitely playing
Jesse Ryder: Main Rival of Tamim. But i want Tamim and JR opening combo and SG at no 3.
Marlon Samuels: Will be busy first few weeks playing Australia
Graeme Smith: Another Rival for Tamim
Steven Smith: 
Luke Wright: A handy opener and a handy bowler so wont be surprise if he gets picked ahead of Tamim.
SO overall, In first few wk's of IPL 5, Tamim have very gd chance of getting in the playing 11. If he does, he have to PERFORM, otherwise i can see him warming up for a long time.