To be honest, until last year, I didn't think these two would marry.
But now...with Kate being present at official events (William's passing-out parade comes to my mind), and as RaeMi pointed out, the happiness and poise she is currently showing really could mean a lot of things...

The British royal family is a family that refuses to be drawn into making announcements before it suits them. Everything is "11th" hour with them; they are very methodical with how they handle engagements and pregnancy announcements. Everything is about polish and prestige.
Exactly. In 1947, they denied Elizabeth and Philip's engagement until TWO DAYS before the official announcement came....
