I, like most people, voted Shockwave partly because most of the public find it boring and outdated compared with some of the other coasters that have built in the UK since, also because this seems to be the direction that Drayton Manor are moving away from. They have definitely found their niche in the family friendly market. Thomas Land and Ben 10 have done wonders for them and I think that any new coasters, even if thrill rides, will have a family element to them and a lower height restriction to match, think Spinball, Cobra, etc.... this is the sort of major coaster I can see Drayton installing. Shockwave just doen't meet Drayton's new image.
The next to go, believe it or not, I think will be Nemesis. It wont go any time soon as it's loved by the public, but with more and more thrill coasters being added, it's popularity will eventually lessen and unfortunately Merlin are the sort of company that believe every ride to have a shelf life.
Blackpool Pleasure Beach are all about restoring and preserving old rides and The Big One is a massive icon, not just of the Pleasure Beach, but of Blackpool itself. It's sure to stay there for a long time.