LN-KGL, I'm not sure what extensions to T2 MAN, or you, have in mind, but it shouldn't take a decade, surely! It depends how advanced detailed plans are, but even if the airport has remained very quiet on the subject I expect much work has been done behind the scenes. Not sure how long is involved in getting plans approved, putting out to tender, appointing contractors etc. but I would hope to see something well before then even if extra facilities are opened in stages.
Nevertheless, your final comment about 2% growth is why I previously suggested, slightly tongue in cheek, that MAN may prefer more modest manageable growth given the present infrastructure constraints. I would hope however that they are more ambitious than that and will now expedite much needed development. Whether it was because of the recession and/or MAN has been genuinely surprised at the level of increased activity in the last 2 or 3 years, or whether STN became a distraction for MAG, I've no idea; but I can understand the perception by some that the airport is behind in the game as far as infrastructure is concerned and needs to start running to catch up.