All these new weapons seem to be taking away from the point of an uber...a short period of invulnerability (that takes aaages to build up) but seems that with each update, seems like each class is getting something against it.
pyro: air blast to blow away ubers
scout: whatever-it's-called to stun ubers
demo: can blow them apart
heavy: is fat so can block players

and on other notes...
never used the backburner much - airblast is too useful.
axtinguisher (thanks to millhawk)
and the shotgun sometimes, or more likely the flare gun (so i can then axtinguish them)