Well, I'm not sure what edition you are playing now, but every edition I have ever played has hard time factors -- how long it takes to travel from X to Y, how long it takes to search an area, how often random encounters occur (in some editions), how long a combat round lasts, how long it takes to regain hit points through rest, when spells can be regained, how long it takes to craft an item or research a spell, etc.
It seems to me to be trivially easy to make these things important. In fact, my players chafe at the idea of their characters having downtime when they could be out doing something. YMMV.
Now ain't that the troof.

I once told the players that they would be spending the winter pretty much snowed in in the small mountain village they were staying in. No biggie, I was going to narrate it in about thirty seconds, then get on with the game.
They darn near revolted. "Wait three whole months????!?!?! OMG!!?!?" It totally blew my mind.
They know what Baron McEvilton is doing.
If Baron McEvilton kills 10 people a day, it doesn't take a genius to realize that 100 people will die if you wait 10 days. If Baron McEvilton has posted bans for his upcomming wedding, in 3 months, which will greatly enhance his political power, then the players know they have three months to do something about it, or they will have to deal with a more powerful Baron McEvilton.
That's the problem with hypotheticals. Sure, you've got Baron McEvilton. How do they know these things unless you, the DM, TELL them. In other words, it's not a player resource to be used. It's a DM stick to force them into following adventures.
Do this, or it will be worse later. Do this or very bad things will happen.
How is this not extremely heavy handed rail roading?
Your points about henchmen and organizations are all valid, but they are not new to 4e. People have been doing the same since I began gaming!
RC
Never said it was actually. I think I brought the mechanics point up from 3e which actually had some codified rules for it. If those existed previously, fine, let's hear them. I know Basic/Expert had something for it's Companion (or was it Masters?) set, but, I don't know those rules at all.
AFAIK, the only rules in 1e were, "you build your castle, followers come". That and a handful of tables about henchment that admittedly, we never used because it was just another way the DM was going to shaft us by having the henchmen rob us in our sleep.
Me, I lean a LOT more towards having mechanics over letting the DM wing it. I've just had way too many bad wings.