Lordy, all the greybeards must be going crazy right now. People are writing everyday how great these new wheel things are -- I'm glad I'm younger than 30 or else I'd probably be going mad at all this talk of graph databases, document databases, object databases, etc etc as if they are some great new innovation.
I have to say I'm not quite clear on difference between a graph db and object db.
I was under the impression that an object DB is a subset of a graph/network db. [IANA DB Nerd]
ODBMs? Transactions! Sometimes you need them. Admittedly, not as often as once thought. RDBMs too, but with ODBMs, you have no impedance mismatch.