FCS (which included FCP7) was never in the App Store, and the lack of FCPX as a free download upset a lot of the FCS owners that paid $1000 for the software, and then saw FCPX released for $300. Myself included.
Although, most people ended up sticking with FCP7 for a while until moving to a difference software. FCPX is not up to par with other professional editing software, as everyone knows. I sincerely hope they do not make the same mistake with Aperture X, and improve it and not make it a prosumer app.
I would wait to see what they do with Aperture X, before buying. I would download Aperture the less than legal way, while I wait, to avoid having to pay twice. Then once you have more facts, spend the money to buy it legitimately.