Of course. If we sign a keeper who can command and co-ordinate the back-line, as well as look strong in his own positioning (A big fault in both Almunia and Fabianski), then we should quell our defensive troubles. But you said that he can only be a good keeper if he can rectify his confidence (as well as other eatures), but also said that you'd rather Fabianski. But like I said before, confidence will only come from successful performances in matches. And if he isn't played, then he isn't going to get confidence. Hence the catch-22. Personally I'd like Wenger to either sign a vocal, authoratitive keeper like Federico Marchetti or a commanding defender and a positionally astute and consistent keeper, like Igor Akinfeev.
I believe Koscielny will start immediately this season and I see no reason why Wenger wouldn't throw him straight into the fray. He started Vermaelen straight away last season, even though he hadn't been given that much time to build up a partnership with Gallas, and well...it worked, didn't it? And considering Koscielny's performances last season for Lorient. The fact is, he was one of the best Ligue 1 defenders last season (Not THE best, but one of the best). Not only was this proved by his many impressive peformances last season, but it was also proved by the statistics: 328 Defensive clearances (the most in Ligue 1), 159 Interceptions (the most in Ligue 1) and a 59% success rate in aerial battles (compared to Vermaelen's 58%). There's more of a basis to start Koscielny as soon as possible than there was Vermaelen last season. So I personally believe Koscielny will start straight away, but I'm doubting whether Vermaelen has the maturity or the reading of the game that Gallas had to cover Koscielny's mistakes. So like you, I have doubts as to whether we're going to see an immediate gel.
And beboq, for all his mistakes Fabianski has got quite an impressive record. 16 clean sheets in 34 appearances, apparently. Plus, Fabianski shows elements of being a potentially very good sweeper keeper, and considering how terrific Lehmann was in that role it makes sense to keep battling on with Fabianski, in the hope that he may one day emulate him. That, I suppose, is why Wenger has stuck with him. Having said that, Fabianski will have to do a lot of improvement on his positioning, command of the area, distribution and handling to be even half as good as Jens.