It should be a great clash between these subcontinental teams tomorrow. The favorites will be Sri Lanka of course, since they are playing at home, where it takes a very good team to beat them, and they are also one of the picks to win the whole tournament. Castrol Cricket has predicted their chances like this:
Pakistan struggled to get going in the face of a very disciplined opening burst from Kenya the other day, and it took some great batting from the Akmals, Younis Khan and Misbah-ul-Haq to get them past 300. But where the Kenyans released the pressure, you can expect Sri Lanka to hold on tight and make them pay, especially since their real strength is in the middle overs when their spinners are operating.
Younis and Misbah are doing a great job of holding the middle order together and leaving the slogging to Umar Akmal, Afridi and Razzaq, but I wouldn't bet on that strategy to turn out well with Malinga (and possibly Murali) bowling at the end.
Pakistan's bowling hasn't been great either - the pace bowling has been erratic, and Dilshan and Tharanga aren't likely to let bad deliveries go unpunished. Afridi took five against Kenya the other day, but I don't think he or Ajmal/Rehman are likely to trouble a Lankan middle order featuring Sangakarra and Jayawardene. Pakistan's best hope is to get those two out and expose the soft underbelly of the Lankan batting - Kapugedera and Samaraweera haven't spent as much time at the crease as they would have liked, and barring Mathews, it's pretty much the tail after that.
So to summarize, it all comes down to how well Pakistan's power-packed lower middle-order performs and how quickly they get can the Lankan top four out.
Ideal line-ups (for me):
Sri Lanka: T Dilshan, U Tharanga, K Sangakarra (c)(wk), M Jayawardene, T Samaraweera, C Kapugedera, A Mathews, T Perera, N Kulasekara, L Malinga, M Muralitharan.
Pakistan: M Hafeez, A Shehzad, K Akmal (wk), Y Khan, M ul-Haq, U Akmal, S Afridi (c), A Razzaq, W Riaz, S Ajmal, S Akhtar.
Official-looking prediction: Sri Lanka to win a tight, low-scoring game.