Oh please, Skydrive is really more important than the other cloud options provided. Veteran skydrive accounts have 25GB of space which is a tremendous advantage over lets say DropBox starts you out at 2GB, squeaking up to 16GB if you manipulate your contacts. SugarSync 5GB, Amazon S3 5GB, Google Drive 5GB, Rackspace and Azure is pay from the first GB… the value is clear. Skydrive is a priority need!
Just got the new Surface Pro2 and it’s awesome. It came with 200GB (for 2 years) free on Skydrive so I am trying really hard to find a wordpress backup plugin that works with skydrive. I’d imagine the demand will increase soon with these new surface pro2’s giving away 200GB of storage.
I agree that it definitely can’t be part of the automatic setting. But you could have a button – “Send my backup file to SkyDrive” – that the user could click. I don’t think that this would breach the guidelines.