Well, seeing the groups, if Afg, Zim, Ban, Ire don't surprise any regular 8 teams in first group stage, that would mean NZ, SL, Eng, WI will be in one group and Aus, Ind, Pak, SA in another group of super-eight. [These groups are decided irrespective of where top 2 teams finish in their group. So if Afg and Eng beats Ind, Afg would replace Ind in super-eight group]
1st group (Eng, NZ, SL, WI)
England: They are going into the tournament without their best player (Kevin Pieterson) who becomes even more important in subcontinent conditions. He is probably their only batsman who can dominate a spin attack in turning conditions. They have two good bowlers in Broad and Swann. And a match winner batsman in Eoin Morgan. I expect them to beat NZ. If they can beat WI (which I don't expect them), they would go through.
New Zealand: NZ has always punched above the weight in ICC tournaments. They play well as a team and has couple of match winners in Ross Taylor and Brendon McCullum. They have a good containing spinner in Vettori and two decent all rounders in Oram and Franklyn. They are already missing a big player in Jesse Ryder which doesn't do them any favors. On a big day they rely too much on McCullum and Taylor to fire. At best I expect them to surprise one of NZ, SL, WI. I don't see them making the Semi Finals this time.
Sri Lanka: Being host gives them advantage. They have three excellent top order batsman in Dilshan, Mahela and Sangakkara. And excellent finishers in Angelo Mathews/Perara. Their bowling attack is good, a good death bowler in Malinga and their spin attack is decent with Mendis and new mystery kid the found in SLPL. I expect them to beat NZ, Eng comfortably which would make them go through to the Semi Finals.
West Indies: On paper they have the most T20 match winners. Gayle, Bravo, Russell, Sammy, Narine, Pollard, Smith all can win the match on their day. There problem is consistency which hasn't been there in ICC events of past decade. I expect them to beat NZ. Their game against Eng would be almost like QF. I expect them to beat one of Eng and SL and enter the last four.
So from this group I expect Sri Lanka and West Indies to go through.
2nd group (Aus, Ind, Pak, SA)
This group seems a really tough one to call.
Australia: They seem to have a balanced side. Two good dashing openers in Warner and Watson. In middle order, they have one of the best batsman in world in Mike Hussey. Also they seem to have found another good finisher in Glenn Maxwell. Add David Hussey and Wade and they seem to have batting order for most of conditions. They have a good bowling attack. Mitchell Starc looks the real deal. Stint with Yorkshire has done him a world of good. Also Pat Cummins and Hilfenhaus make good bwoling attack.One thing they lack is a match winning spinner which might hurt them in later stages. But I expect them to beat India and South Africa with a close game against Pakistan. This would qualify them for last four.
India: Once again India has bolstered their team with batsman and batsman. On paper, when in form they seem to have the best batting line up of the competition. But too many of their batsman are not in form. That aside, they have a good opening combination in Sehwag and Gambhir. Their number three Virat Kohli is currently one of top 3 batsman in world. Plus they have good fire power finishers in Raina, Yuvraj and Pathan. Dhoni and Rohit have struggled off late but still their batting is their strength if not thrown on a fast bouncy pitch. Problem with India is their bowling. They seem to have one good bowler in Zaheer, other than him none of their bowlers seems to pose a threat. Pathan, Ashwin, Balaji, Dinda all seem to be one level below the international T20 standards. Their biggest match in securing the last four place will be against Australia (which I expect them to loose considering in form Australian bowling) as I expect them to loose against Pakistan and marginally win vs South Africa.
Pakistan: They have the best bowling attack in the tournament. In Ajmal, Gul they have 2 best T20 bolwers around. Add Afridi, Hafeez, Razzaq and their bowling looks sorted for all conditions. Their weakness is their batting. In Nasir Jamshed they seem to have found a good top order batsman. Bringing Kamran Akmal gives them better balance. And Umar Akmal is their best batsman. Their problem is inconsistency of Nazir, Malik, Razzaq and Afridi. Each of them is a match winner on their day which seems to come once in a year. Despite that, their batting is going to have their workload reduced because of their brilliant bowling. Their toughest test would the game when their bowling/fielding will have one really bad day and they would have to chase 160+. Other than that they are the easiest pick for last four.
South Africa: They have two really good anchor-role batsman in Amla and Kallis, one really explosive- consistent batsman in AB DeVilliers and two good finishers in Albie Morkel and Duminy. But their batting still looks short of the fire power required with no back up considering how poor is their bowling. Dale Steyn is not a great T20 bowler especially in subcontinent conditions and Morne Morkel is inconsistent. They don;t seem t have a go-to-bowler when batsman are going all attack. They have a good T20 spinner in Botha with decent support from Peterson. I think they made a big mistake by not selecting David Miller and Imran Tahir which will hurt them against good oppositions. Kallis gives them a good balance in their side less so in subcontinet than in say like England. Even then, I don't expect them to beat Pak and Aus which doesn't qualify them for my top four.
So there you go, my Semi Final picks are Sri Lanka, West Indies, Pakistan and Australia