Earlier this afternoon Microsoft launched Office365. I had a play with the beta over the past couple of weeks. The online experience was pretty smooth; much better than BPOS was at the same stage. I am not convinced that an ordinary user will not be able to do a smooth deployment of the on-site piece – yes; you will likely use Office on a PC instead of the web editions, just because of mobility and usability. You will download a client to (allegedly) configure Office. I found it downloaded, ran for a while, and did squat. Anyone with an AD or Exchange to integrate will need to work with a specialist partner to do the synchronization and/or migration. Note that there is a SKU (or a set of them) that include an on-PC Office 2010 license that you are entitled to use for the life of your Office365 subscription.