Consoles will remain relevant until someone streamlines PC gaming to the point where joe public doesn't have to scan a block of minimum system reqs to know if their tower / whatever is good enough.
This would change if say Steam released one version of Steam Machine, and every PC release that could work on it both had a sticker on the cover (or just a SM-specific partition of Steam) and have an "optimized for Steam Machine" setting.
And as for streaming replacing everything...heh. Maybe in the far-flung future, where internet doesn't suck ass in large swaths of even 1st world countries.







