There is some functionality coming along to GitHub soon that I must admit to really looking forward to. It won’t change the world, but it appeals to my geeky side. Rather than my normal flood of words, I used this feature with a bit of PHP script and the DOT drawing engine to produce the following diagrams. So what is the new feature? Sorry, you will just have to wait until its ready.
Disclaimer: The following data model diagrams have not been verified for correctness – I am sure I don’t have the UML symbols completely right. This is a bit of fun, but showing the potential of some of the newer features to help describe the Magento data model in a more palatable form. There is no commitment to include these diagrams with the product (unless enough people think its worthwhile considering!)
CMS Page (as simple as it gets!)
Customer (click to enlarge)
Cart
Order
Invoice
Shipment
Product (does not include all the product types)
Alan Kent's Blog 
Hi Alan!
I am so excited, you are really killing the EAV model?? Wow, this is so great, I can hardly express how suprised I am by this move.
Is that the outcome of what I shared with you in Berlin and earlier this year (Spryker)?
Mit besten Grüßen / Best regards Björn Kraus
I did not say what diagram was exactly. Sorry to disappoint, but no, we are not killing EAV model this close to GA and during Merchant beta. That will be reviewed if we clean up persistence abstraction in future release.