When can I upgrade? Will the new version be available at the same time for online and on premise customers?
What if I'm on Dynamics CRM Online? Will I be forced to upgrade? Can I schedule the upgrade?
If I'm still on Dynamics CRM 4.0, should I upgrade to 2011 and then to 2013 or go straight to 2013?
Here is an excellent blog post on the subject from Intergen.
Microsoft has tried to make the upgrade as painless as possible while packing in as much new innovation as possible.
You cannot get the most out of the new version without considering how new features impact your users and by providing training to help people discover new features and take advantage of them.