After one day at NoSQL East, I believe I can do a quick compare & contrast with OpenWorld.

NoSQL East

Oracle OpenWorld

Cost To Go $600 $2500
Location Atlanta GA San Francisco CA
Number of Attendees 125 40,000
Laptop % in use during talks ~95% ~10%
Typical dress T-shirt & jeans Business Casual/Suits & no ties
General Content Much more technical Much more marketing/sales
Number of vendors in the expo hall 0 (no hall) ~500
Number of concurrent sessions 1 18

None of this should be construed as a slam on either conference; they are each focused on different demographics.