Photoshop CS6 (ACR 7) and Lightroom 4 have PV2012 as the default for RAW editing. Photoshop CS5 with ACR 6.7RC will render a RAW file that was adjusted using PV2012 in either CS6 (ACR 7) or Lightroom 4, but you can't make adjustments using PV2012 in CS5, I expect the same is true in Elements if it has an ACR converter equivalent to the ACR 6.7RC in CS5. You will have to wait until a new Elements is released that uses PV2012 for RAW conversion instead of PV2010.
Whenever ACR is released, there is an installer that works with whatever the current version of Elements is. Elements is updated to a new version in or around the September timeframe.
ACR 6.7 is in public beta and ACR 7 is also in public beta as part of CS6. I would expect that ACR 6.7 will be finalized in the coming weeks and then an installer will be available for Elements. I would expect CS6 and ACR 7 to be released in the coming months and an installer for ACR 7 be made available for Elements at that time.
As already stated, ACR 6.7 does not have sliders available to make PV2012 adjustments, but understands how to render them if another Adobe product, like LR4 or CS6/ACR7, has created them. ACR 7 will have the PV2012 adjustment sliders available to the user, so that is the one you’ll want to wait for to use Elements free of using PS-CS6.
I would expect both ACR 6.7 and ACR 7 to be available before September so you should be able to use your current Elements with the updated ACR w/o buying a new copy of Elements.