Thanks to Sitecore we have license for the MVPs, but what can I do with it? Is it allowed to share it with a direct colleague to do some research? Or can I use it for a client presentation? Is there any place where I can find the rules around that MVP license?
The best source of usage rights are defined in the Sitecore MVP Program Agreement:
Sitecore hereby grants MVP a non-exclusive, non-transferable, non-assignable, non-sublicensable, revocable, limited license to use the Pre-Release Software and Released Software, in compliance with all applicable laws, in object code form only, solely for evaluation, research and development efforts consistent with the solution implementation and product evangelizing goals of the Sitecore MVP Program.
You can use it only for personal purposes: installing Early Access software, develop an open source module, testing and learning new features and this also includes running your own blog or hosting an open source project.
You cannot give it to anyone else, you cannot run any client solution with it, you should not use it to demo/sell Sitecore; for any of these activities you will need a partner license or a demo license.
If you know someone who would like to try Sitecore please refer them to the free Sitecore Developer Trial Program