Neerfate: indeed. Also, one should not forget probably the cheapest and most effective tool of the multiclasser -- paragon pathing into another classes path.
And frankly, there still are the occasional power worth a swap feat for, even if they're rare.
For instance, my Avenger (Artificer) / Battle Engineer took a swap feat for Slick Concoction (minor action, close burst 3, slide allies in burst 5 squares and they gain +4 reflex). First, there was very little for me in-class; Avenger U10s are pretty mediocre -- probably the best is Avenger's Readiness (initiave daily; shift 3 and +5 init), and there is a 2 round/encounter flight, minor action self-healing, and a teleport/drag power, but the rest is just terrible. Whereas Slick Concoction is amazing; at minimum, it hands out a move action to most of the party, letting the party more easily get in charge range of a foe at the beginning of a battle; more often it sets people up for a party nova, turning on my unity powers and/or gathering people up for Greater Magic Weapon (or splitting them up afterwards).
I could have easily swapped for Vorpal Edge at 16 if I wanted to go crit fishing instead of helping out my crew, too.