You should be able to inject IProductInfo. But since we've changed how products work (they're essentially plugin packages into a base product), this might just get you the product info for the base product (e.g. "ReSharper Platform"). Also, since an extension has to be recompiled for each minor release, you already know at compile time what *product* version you're targetting (e.g. 9.1, 9.2, etc.) although admittedly, this is different to the final build version number.
You should be able to inject IProductInfo. But since we've changed how products work (they're essentially plugin packages into a base product), this might just get you the product info for the base product (e.g. "ReSharper Platform"). Also, since an extension has to be recompiled for each minor release, you already know at compile time what *product* version you're targetting (e.g. 9.1, 9.2, etc.) although admittedly, this is different to the final build version number.