Everyone Roll Initiative...

I find the Initiative Roll to be a double edged sword. Positive side, I find that when a DM says "Okay, everyone roll for initiative" that's the que for go time or the change in music just before you get into the Bos room.
On the down side...it can possibly be a big momentum breaker as everyone starts rolling and then you hear:
"22!"
"15"
"I got a 7"
"26! Fools!"

"I got a 7"
"Hold on hold on I'm still writing. Did anyone roll more than 15?"
"I got a 7"

*sigh*"4..."
etc.

Not usually a big deal but with larger groups with players ranging from all levels of experience as well as attention spans, there are situations where a lot of time has passed from the point of rolling d20's to when the first person does his/her turn.

Another thing that I don't like is when there aren't minis being placed on the table and the folks who dislike skill challenges might lean back and go "Oh great another skill challenge" before anything has even happened.

I'm planning for the next session that I DM to have a bunch of Initiative Rolls done before we actually start playing. Change up the amount of sets of initiatives being rolled vs how many encounters I actually plan to set up that night.

Plan to do four encounters that night? Make them all roll 6 initiative rolls and the encounters will be assigned out of order to how they might play out that session. My goal with this is to start fighting right away or to catch them off guard when a skill challenge is starting. For the latter, it's really a goal of mine to have people who do not like skill challenges be taking part in it before preconceived judgment can take place. It's simply "Thalos raises his eyebrow in a disgusted yet confused manner? You notice his fingers shifting on the edge of his sheath. Adam, what do you do?" And the order of initiative has kicked in, be it combat or skill challenge.