Many of the rituals seem to be mostly useful in situations where you DON'T have the time needed to cast them. Chameleon cloak, Memory Seal, and wizard's escape, for example. Perhaps there should be some means of "precasting" rituals and then "releasing" them? A Feat which lets you "store" a single ritual? Something...
That way lies Vancian casting. Been there, done that, don't wanna go back.
The extended casting times are features, not bugs, IMO. Sure, the memory-blasting ritual would be incredibly useful for getting past guards and the like. So useful, in fact, that it would severely devalue all the non-magical ways to get past guards. Hence the restriction.
But think about the other circumstances you'd want to use it in. Sure, there will be cases when someone will willingly submit to it ("You must forget the location of the safehouse before you enter the lair of the mindflayer!"), but most of the time, you'll want to use it on an unwilling subject, and while you can engineer things to make it possible, it often reaches the point where it's easier to just kill them.
This may be the first "must have" article they have done in the 4E era.
To echo earlier comments, I hope it makes into the compendium, and sooner rather then later.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.