Rather unfair to use the EXADATA2 description
It is rather unfair describe technology that IBM has had for 15 years as an EXADATA2 knockoff. DB2 on the RS/6000sp boxes where shared-nothing MPP with message-passing when Oracle was SMP and using the disk cache controller to ping pages between instances.
Oracle is playing catchup.. the only difference being the growth of the dedicated database-computer market.. and lower infrastructure costs.
Unless Oracle can get CERN to fess-up to using its product for the LHC, you can expect IBM to trounce them again..