I bought the trial DVD of CS4 to try EX1 footage in CS4 but the trial version DVD came with NO EX1 support! I do not know if the codec is still in the software or not but when I opened a CS3 project in CS4 it did open after going thru a *conversion* process. Now I dunno if it is just a proxy or what!
I've edited hours and hours of the stuff in CS3 native. The 3.2 update adds support for XDCAM EX.
The trial versions (CS3 or 4) will not have this support as the MPEG 2 decoder is not included in trial versions. Adobe would have to pay for the MPEG 2 license for each downloaded trial version. Full versions of CS3 and CS4 have support for XDCAM EX natively.