A chap called Steve Rubel, who is the author of Micro Persuasion (one of the blogs to read) has 'exposed' the myth of brand engagement - he reckons it doesn't exist. Check out the full article here on AdAge (another good thing to be reading) but I'll summarise - brand engagement doesn't exist because consumers don't want to engage.
Want consumers want is to connect to people in networks. The sites that facilitate this are booming - Youtube, MySpace, Bebo etc etc.
Steve Rubel is basically approaching the issue of marketing and advertising from a completely new angle - from the point of view of the consumer, not from the point of view of the brand.
Instead of a brand saying "we need to get people more engaged with our brand" they should be saying "how can we make our brand more useful?" By focusing on making the brand more useful (think Amazon's efforts to personalise your experience with all those "people who read this also read...") people will become more engaged with it, because the brand can do more for them.
This again is something that brand experience agencies are going to have to come to grips with, because events aren't enough anymore...but that's just my opinion.
CHeers
Steve