Sounds like the difference is that pre-4e lots of things did damage *or* an effect, where in 4e they've been combined.
That seems an accurate description.
In 3E, many "tricks" were easily repeatable - you could trip, bullrush or disarm at will. It would have been totally unbalanced if these options also allowed to deal damage, because they would be superior to regular attacks.
In 4E, they took away the repeatability by making stuff encounter or daily powers, allowing you to still deal damage with such powers. In a way, this makes a lot of sense - why shouldn't an attack that knocks you down not damage you? Especially if we're not talking about spells (magic can work as it likes, it's not based on reality), but about weapon attacks - a stunning fist attack certainly should deal damage, because you're hitting the guy hard enough to stun him!
In this context its interesting that the designers decided that Trip (not a standard combat option) was still way more powerful then Bullrush (anyone can do this at will, and some at-will powers grant the benefits together with damage, like Tide of Iron or, effectively, Scorching Weave), while 3E still treated them as mostly equivalent. Maybe it's just because being prone now grants Combat Advantage (and thus sneak attacks are allowed), or it is because it grants you a bonus to your next attack and costs your opponent an action (move) to undo. A bullrush
might require a move action to undo, but any bonuses are highly situational...
I've bought and read the PH, the DMG, and about 3 adventures, one of which I'm currently running ret-conned to 1e...I'd like to think that's enough to at least get the basics.
Hmm. I don't really know if that is enough for the basics (but what does "basics" really mean) - of any game system. Many people assumed the 3E Monk was overpowered, but once they saw them in play, working in a party and applying stuff like the wealth by level guidelines in practice, things looked different. I am not sure even the designers understood the implications of being able to create/buy a magical item worth 750 gp that could heal a party after one or more encounters to full hit points.
The customs agent was such a prat that my Illusionist wanted to show him up a bit, so she spent about 10 minutes on a Minor Image (it was a 3e game) to ever-so-slowly "move" the gangplank to the dock about 3 feet to the right of its real location - and sure enough, he walked right over the side into the bay! Now if a 4e Illusionist can do *that*, we're good to go!
I hope the designers had some such "at-will" minor illusions in mind. (I wonder if Illusionist will also have access to cantrips...)