I hope they do put Bell back at 3 - and then try a young batsman down the order! Surely you wouldn't want to give someone their debut in such a big series?
In terms of youngsters - James Taylor would be the first in line. Batting average just under 50 (52 this season), although he's a middle order batsman rather than opener at present - and given Strauss is likely to be the next one to go that's what we need to be looking at really, unless Trott was to open. James Hildreth seemed next in line but he's not had a great season, same for Michael Carberry.
Alex Hales is coming along well, but he's a few years away yet, same with Joe Root. England do seem to have a good crop of young players who have just come into the county scene and could well come good in 2-3 years