It only took a year... to quote hmxsean via RockBand Forums:
Hi Everyone: PS3 ROCK BAND DISC EXPORT TITLE UPDATE
First and foremost, we’re happy to announce that PS3 users will soon be able to export RB1 songs to their system in advance of the launch of RB2! A PS3 patch will be coming out this Thursday, September 11th, which will allow RB1 song export, in addition to updating DLC to our RB2 standards (so you can continue to rock the newer content in RB1 if you so choose!)
This title update will also patch for the use of the Guitar Hero III Les Paul PS3 Controller with RB1 on the PS3. We're excited to release this, as controller compatibility is something we've been working towards for a long time.
This Rock Band 1 title update is set to come out next Thursday. As with the Xbox 360 Title Update, you will have to update Rock Band in order to play any DLC that is released after Thursday.
This leads us to the PAX pack which was released yesterday on the PlayStation Store. Due to technical issues with the submission of "Livin on the Corner of Dude and Catastrophe" by MC Frontalot, users who downloaded that track or the entire pack found that they were not able to play this content in the game. Furthermore, downloading the pack meant that all 3 songs in the pack failed to load.
We're aware of this issue and are taking multiple steps to fix it. We are resubmitting the tracks to Sony today and hope to have fixed content up on the PlayStation store as soon as possible. Users will then be able to replace the broken tracks by re-downloading this content for no additional charge. If you don’t feel like re-downloading this content and can wait a week, the title update that is launching on 9/11 will fix it automatically. We appreciate your patience.
Again, we're dedicated to bringing you the best in weekly content for any music game out there. We're transitioning from single title Rock Band DLC to a cross-title DLC system which will allow you to play your DLC in both Rock Band 1 and Rock Band 2 DLC (an industry first!), so we hope you can be patient as we figure out the little hiccups here and there.
HMX Community, PR, and Audio More PlayStation 3 News...