No one knows who can say, as Adobe doesn’t pre-announce future capabilities.
I believe PSE12 is due out very soon and I suspect it’ll have ACR 8.2, which will edit 70D files. I also suspect Adobe will not allow ACR 8.2 to work with PSE11 unless they change how they’ve done things in the past.
You can always convert your CR2 files to DNG files and edit those with an older ACR version. Right now the only version of the DNG Converter is DNGC 8.2 RC available at Adobe Labs:
But when the final version of ACR 8.2 is released in maybe a week, then you can use the final version at: