I'm sure the producers are keenly aware of what they're doing. Getting the wedding out of the way now, allows for more screentime for Ted and the Mother in the finale.
I mean think about it ... when you walked out of Attack of the Clones, didn't you basically have a running list of things that you knew were pretty much guaranteed to be showin in Revenge of the Sith?
I applaud the producers for defying our expectations (again) and for telling the story they want to tell. Last night's episode was good. Not great, but it finally once and for all solidified that Ted was over Robin and that Robin wanted to be with Barney. Marshall and Lily stole the show though with their vows, although "Stinson out!" was pretty amusing.
We didn't need another tracking shot of all the recurring characters we wouldn't get to see again like last week. This was just another episode of HIMYM and it was delightful.
And Robin finally met the Mother!