With no Malinga and no Murali, I'd expect Pakistan to win the first test pretty easily, maybe even the series!
Not sure I share your lack of faith in the Sri Lankan line-up. Will be interesting how Sangakkara organises his troops, and in the long term puts his stamp on the side, but in the short term I expect his batting and that of his team-mates Jayawardene, Samaraweera, Dilshan and potentially debutant Kaushal Silva,should they opt for a specialist keeper, to ensure SL are competitive at the least. Certainly I hope they select Silva as keeper, Sangakkara will have plenty on his plate without keeping, and would prefer Dilshan to concentrate on his improving Test record.
Angelo Mathews enhanced his reputation in the World T20, and I would like to see him in the side at some point, perhaps just not yet.
With Mendis in the side, SL will be a threat in home conditions, despite the Pakistanis having played him well so far, this time he will be the leader of attack, the man Sanga will look to get the vital breakthroughs, interesting how he copes with such pressures.
The pitch may hold the key to this opening Test. I understand there's been a lot of rain around, and the fact there will be be a Test is quite something. Whether it's a slow-turner resulting in a high scoring draw or a track with a little more life, it may dictate the level of excitement in this opening Test.