I wrote an article a few months ago that appeared in Australian Reseller News about what Microsoft partners need to think about with SharePoint Online as quite commonly I heard them refer to it as a file storage or document management system. You can read the article at the ARN website (annoyingly the cut it short due to word count limitations and damaged the context and ending).
Quite often when speaking with prospective customers they tell me about their gigabytes of data dating back many years, and so when the topic of storage space in SharePoint Online comes up they immediately find the storage limitations and pricing unattractive. So each time I go through the process of educating them about that SharePoint is not a file system, and that SharePoint Online is the same as raw disk services such as DropBox, Box.net and myriad of other services popping up every 5 minutes.
So I sat down and re-wrote the article to be more aimed at customers, looking back at their IT partners. You can read it here at BoxFreeIT.