Never read a single issue of the Vertigo series, so I can't say I'm broken up.
The reintegration of Vertigo characters into the DCU is probably a good thing--with this caveat.
Done right, a character like Constantine can benefit from his unique corner of the DCU, much like Dr. Strange. The problem is there's a big push to fully integrate 'shared universe' characters in places where they don't fit.
Dr. Strange is a great example. He should really be dealing with threats the rest of the MU doesn't even have a name for, and none of the heroes should be entirely comfortable working with the guy. I mean, if Doc Strange shows up, you know some serious #$% is about to go down that you can't handle.
So it will work if it makes for a constrast. Getting Supes or Batman's reaction to unseen worlds they can't fathom. I mean, the capes aren't used to that and don't handle it well. That's fun. What's not so great is when everyone gets ho-hum about it and they've got Doc Strange or Constantine on speed dial and want them to join the Avengers or the JLA.