All API's morph. Its more a matter of respectable lead times. Amazon usually gives a decent lead time when changes are going to come about for example.

I did speak with one of my pub friends (we usually meet Friday night and slosh down a few Sam Adams) earlier tonight who called me. He was both surprised and not at Facebooks lack of concern over WP installs. He's an educator at our well known tech college.

From a marketing standpoint it makes sense and from a technology standpoint it makes sense.

They are going to get loads more activity through mobile devices since that is the burgeoning market at this point in time. With corporations such as Adobe, Amazon, Microsoft to name a few known entities working towards the drag, drop, configure, associate online publishing it favors Facebook, Twitter etc. to work towards whats coming .vs. whats been or what is.

All these corporations are aggressive so when you see them make moves and NOT make moves its not just "well we had a thought or forgot about it". Everything is studied quite intensive when it comes to markets. Facebook isnt ignoring an application that has 20% of installed webs unless they see the future as that dramatically changing.

Ive said it before, I'd not be surprised in the least if an entity such as Microsoft leads the charge in porting WP to .NET or even buy the company. 20% of market share is a BIG jump start.