It seems to be mainly a problem of low-level characters vs solos. I think we'll have to wait a while to see if it's repeated at higher levels.
I'd certainly suggest asking your DM to throw a large group of weaker creatures your way - 4e works really well in that situation.
I think 50% hit rate is pretty fair.
What's strange is I remember something about WotC modelling 4th Ed math on that test/experiment or what have you that showed that the human brain enjoys a 70% success rate in games.
The question is: is 50 % hit rate the success rate using no tactics, or is it already taking into account combat advantage and use of powers?

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