could it be the HR/recruiting dept are struggling or understaffed to keep pace with the current recruitment drive. I'm just on 7 weeks since interview - it's a bit stressful remaining in limbo, and I won't stop pacing until I've signed something....Hurry up and wait! At least we have the warm fuzzy feeling of being in the same boat
as for tips on the interview, what has been said in posts dating back last year still hold true, no new surprises, all quite relaxed and friendly process