The IDE has had to be re-written for 32bit code. This means that ALL functions needed to be re-written for 32bit.
Arduino are working with Atmel directly and have had to work pretty hard on the liciencing of atmel code to fit the 'open source' model with the IDE. I think these two things alone have been some of what the hold up has been.
Its not as simple as just chucking another board out there and adding to an existing architecture IDE.
The signs are that the google android dev board is ready and based off the same techonlogy so it wont be long. I for one would prefer a nice stable product / IDE so its worth the wait.
The down side to all of this is 32bit libraries are going to take some time no-doubt
I cant wait for full colour 32bit oLED