If the England bowlers turn up tomorrow and bowl as we know they can, they should be able to dismiss SL before they get within 100 of England's total.
England then bat for the remainder of day 3 and two sessions of day 4 and if they put their foot down a bit, a lead of over 350 should be easily possible.
On day 5 the dry pitch should be turning a fair bit and Swann will be a major threat.
This is all so long as the weather plays ball, which is somewhat uncertain.
Or perhaps I am a touch too optimistic.