Official Answer:
If you like flowery marketing words then check out the description on the site http://www.microsoftcloudpartner.com/ else read on.
Short Answer:
It is an awesome FREE offer to Microsoft Partner Network partners to help them get on the Cloud and to help them build software products running in the Cloud. Cloud Essentials includes many benefits such as BPOS and CRM licenses as well as monthly free allowances for the Windows Azure Platform. This is the bit we like :-)
If you are a partner who develops software then:
Longer Answer:
The Microsoft Cloud Essentials Pack includes:
Plus other marketing and business benefits, which as a techie go straight over my head :-)