QUOTE(Kelly Martin @ Tue 8th March 2011, 10:10am)
QUOTE(Zoloft @ Tue 8th March 2011, 10:48am)
Ultimately, if MediaWiki fails to move away from PHP, this by itself could be what kills Wikipedia.
Jimmy Wales, and by extension Wikimedia, is far too conservative to "gamble" on a platform change at this late stage of the game. In Wikipedia's ten years there has been almost no functional or technical change in the Wikipedia platform. Contrast Facebook, whose current platform bears absolutely no technical resemblance and fairly little functional resemblance to what it was like when it premiered.
In agreeing with you, I will differ to this extent; the WMF has enough cash to parallel-develop MediaWiki 2.0 while maintaining the 1.x line, then bringing up servers with the newer, faster, more scalable version and importing the database and links.
Properly managed, very low risk, really high upside.
I'm lazy enough to assume without even looking that no such development is actually planned.