The reason I don't think we'd see EZY is that they don't have enough bases in the locations we want. The only base they have that we want, and FR doesn't is Paris Orly. With a LCC we could have three rotations to there all year round or at the very least February to September.
EZY could do LGW as well but not as successfully as Flybe could with either a Dash or Emb. As they would be able to do 2 profitable return routes morning and night, were EZY could only do 1. BE win's out on flexibility.
With recent oil rises too, the true LCC's are becoming less and less cheap, whilst BE with it's fuel efficient fleet are keeping prices steady.
Eventually, probably by 2013, I see BE with routes to EDI, LGW, either BRS or CWL, either LBA or NCL and if we were really lucky a route to Paris.
I still have my bets on Jet2 as the third airline to enter. It'd be perfect for the sun routes with the right sized 733. It would encourage FR to take us more seriously whilst drive value and routes on offer. Finally, at least their announcement would be followed by good advertising campaigns... remember Muff!