Looking at it from a business perspective ... EI are not a big player and don't have very deep pockets.
Therefore, if you're going to set up shop in someone elses back yard (don't forget that while they're allowed to open up in another EU state, doesn't mean they'll be welcomed with open arms, especially by the incumbent "flag carrier") you'd better make sure that either;
1) The market is big enough to support 2 players (especially if you plan expansion)
2) You have a very unique sellig point (hence the loco success)
3) You can out last the competition in a fight
4) There is a large pool of locals who will automatically switch to your brand
On the back of that, can't see Berlin as a runner. Anyone have details on how financially sound the main eastern European carriers are?
JAS