Ok I love my HP server, but I cam across this and I do find it interesting.

http://www.tranquilpc-shop.co.uk/acatalog/AVA_RS5.html

What is interesting to me is it comes with a built in dvd drive (can be upgraded to blue-ray).  So what is it using to make copies of the movies straight to the server.  Sounds like you just put a disc in and it works it's majic.  Then you can start streaming movies.  Is this something that if you simply added an external blue ray drive to the hp unit you could do?  I would think you would have to add some software (anydvd). 

http://www.tranquilpc-shop.co.uk/acatalog/SQA-5H_Accessoriessub.html

This is an external eSATA add on that says it supports 5 drives.  I wounder if the EX475 would see all 5 drives or still be stuck to only seeing 4?  Side note I have seen the ex470 and ex475 selling for more money that the new units.  Guess people want more than one external esata drive.