Personally, I'm oldschool all the way. It's nice to have small objectives to do just as long as I'm not, as it was already mentioned, "forced to". A good example is the current Valve release "Left For Dead". Not a single object to slow down the gameplay. For those that haven't played LFD it's simple; go from safehouse to safehouse shooting as many creatures as you can, and there are plenty. Main point: just survive. You do have a small objective along the way: search everywhere for medkits, pills, pipbombs and molotovs that aid in your survival. What's amazing, and the main thing I look for in game design, is the replayability. A few of my buddies and I will play online for literally hours the same campaigns; 4 campaigns each with four levels. Addictive as hell.
I beleive game designers today rely too much on story lines with they're annoying cinematics; they're ok the first time but I hate to have to sit through them over and over. If I want to watch a movie I'll pop in a DVD, lol. I've been designing levels (maps) for Sven co-op (a modification of Half-Life) for 5 years now and each map I made focused on gameplay.