Sorry Hasbro*, Cat's out of the bag.
First off, much of there collection is already out there. There are torrents all over the net full of their old stuff; suspending the PDFs of Aurora's Whole Realms Catalog is isn't going to fix anything**.
Secondly, if you have a problem with selling PDFs of your books on the internet QUIT PUBLISHING YOUR HOUSE MAGAZINES IN PDF! Honestly, I have a DDi subscription and occasionally I've grabbed articles off torrents because I don't feel like logging in to WotC's site. You want to make it difficult to pirate, PRINT THE DANG MAGAZINES ON PAPER AGAIN!
Third, don't think this is going to stop pirating. As long as there are people willing to take a book, rip it apart, and scan/OCR the thing, their will be PDFs. Heck, the 4e books were released BEFORE the print mags thanks to an employee releasing the print-proofs. Will it slow them down? Sure. Stop it? Not by a longshot.
WotC SHOULD have tried to go with an iTune's method; charge a price so low that piracy becomes less attractive. Charging full price for a PDF was ludicrous. Actually, I miss WotC's "buy the book, get the PDF" model (as impractical as it was). Most PDF buyers do so to keep a searchable copy on a laptop for game. WotC convinced some to buy the books at full price, they would've convinced more to buy them at 1/2 price, but now they are forcing them all into piracy.
Someone should reconsider this choice.
* I say Hasbro because I bet pistols to pesos it was a Hasbro, not a WotC beancounter, who noticed the loss in revenue and ordered the stop.
** Really, all pre 4e items are out of print. Whose sales are they hurting? Ebay's?