Windjammer
Adventurer
I can completely believe it's a stealth 4.5 update.
And, for the record, I am 100% fine with it. Even excited about it, honestly - there's a marked quality gap, IMO, between the PHB1 and later releases. 4e didn't hit its stride until a while after the Core 3 were released.
-O
Totally agree with the assessment, with e.g. the Paladin class's reworking in Divine Power being a pretty much inarguable case in point. I'd also mention Arcane Power making the wizard more of a controller as a clear indication that the initial design was found lacking.
But personally I haven't noticed a similar trend, comparable to the improvements in 4E's class design, as far as the base rules of 4E are concerned. Ok, so there's a useful errata on Stealth that made it into PH 2. But what else is there in the rules "updates" since 2008 that's really an improvement as opposed to smoothening out some rough edges that caused trouble in LFR play?