I think at the moment it's probably still more value to have your BI cubes locally, unless most of your IT architecture lives in the cloud, it's going to be that little bit easier to supplement your established cubes with additional information from systems within your data centre.

In short, if you put it in the cloud you have the added complication of putting (and therefore assuring and complying with security concerns) your information to the cloud. We have a BI architecture just being developed but working for local government it's unlikely we'd ever have BI in the cloud due to the nervousness of securing information hosted by a third party however irrational that may be.

TL;DR To finish I think thereis no real reason to move your cubes just because your source has moved, and there are more advantages in keeping it local than pushing it to the cloud, unless your whole IT estate is in the cloud, and if so... meh.