Pace,
it will eventually become dated but the addon industry does a lot to prolong that process. The primary concern is that FS X is actually no longer for sale. Many in the industry however say that with the very long time that FS X is now on the market and a stable platform (after SP2) it gives developers a much needed time of stability to get their addons right, rather than rushing them from one variant to the next.
Like Windows XP, which is outliving Microsoft's wishes for 2 new windows versions now, FS X will soldier on until something really new that replaces it will appear. And this will most probably not be "Flight!"
Best regards
AN2 Driver