The Oracle Exadata Special Interest Group under IOUG has taken off informally with over 100 members now. Please visit the Linkedin site to keep informed about the Oracle Database Machine / Exadata related webcasts. The next one is on April 16th, again check the above site to register for it. These webcasts are brought to you for free.
Oracle University has started offering paid education on Exadata as well. The virtual classes cost $600 and more details are here:
Shyam V Nath