Some people in the Philippines are speculating that this set will be a real pain in limited play.
I posted my Prerelease decklist below, and could have doubled my removal had I gone R/G/B, but felt that good cards like Sunscape Apprentice, Samite Archer and Ordered Migration (plus my U/W inclination) made U/W/B a better choice.
Hey... I felt I got a lousy Sealed Deck with Probe as the star card!
Anyhow, it seems to make Sealed Deck a little more interesting, but other things like Draft and Team Sealed REALLY interesting.
I think that draft is bad because of Gold. You could draft two color decks with a splash at one time. But mnow you have people drafting three colors spread evenly. I like Black/Red in draft for Invasion. But if the guys at mty table are drafting 5cc or something it can really get screwy for everyone. The Harrows, and Elves and sac lands and duals make it very difficult to get a consistent draft. I am definately more comfortable with Sealed. Team sealed can rock.
There are enough cards that you can start to make your Limited decks look constructed.
I think invasion makes draft (particularly rochester) a lot more skill based (and also political). No more nudge nudge, wink wink signals because gold cards will draw people into each other's colours. I think at PT level once the format is tested, we'll see messages becoming much more strategy than colour based (as players indicate they are drafting more for beatdown or control, and colours matter a bit less). But at PTQ's things will get downright ugly as everyone things they are calling a colour, when their neighbor feels they must pick it as well. For this reason, I expect B/R to be a very popular draft choice, as blue and green will get quickly grabbed by all as a splash or joining colour. White mages will have to be very careful (or sandwiched between a pair of B/R guys).