Every camera model must be supported individually so the extension being the same doesn’t matter as much as Adobe having profiled the camera and added support.
PSE 10 will never be updated to support the 70D. You’ll need PSE12 which should be available in a month or two and make sure it is updated to ACR 8.2 at that time.
In the mean time there is a beta (release candidate) of the DNG Converter 8.2 that you can use to create DNGs from your CR2 file, and those should open in older versions of the Adobe Camera Raw plug-in such as what comes with PSE10. Keep in mind that the support for the 70D is “preliminary” which usually means the color profile will be tweaked to give a better conversion for the final release.
You can also use LR 5.2 RC which has preliminary support and use Edit In Photoshop Elements with LR Adjustments.
The release candidates for LR 5.2 RC and the DNG Converter 8.2 RC are available at Adobe Labs: