[LoonyPandora]

Apple haven't announced which machines will be compatible with the released version of Mountain Lion, so it's premature to say that Apple are "blocking" it. "Blocking" is also different to "Not Supporting"

Minimum specs have changed between beta and released version in the past. Apple has also released firmware updates to make machines boot in 64-bit mode as well. It is well within the realms of possibility that your machine could become "compatible" before 10.8 is released.

Secondly, as a point of reference the current MacBook Pro's do have upgradable hard drives and RAM. However the battery is not easily replaceable.