Can you crate one and leave the other out?

My 6-year-old dog, Eevee, is let to roam the house, and my 5-month-old, Shippo, is crated while I am gone. Shippo MIGHT earn the right to roam the house eventually... we'll see.

In the past I've had a mature dog in the house while the youngsters were crated.  You may have to worry about the crated dog getting upset, but that should pass.

Of our 4 dogs, the youngest being 5 years old, 2 are crated, 2 are not.  The two crated do not seem to have any problems being so while the other two are out.

Yes, you can certainly leave one out while the other was confined. 
 
However, why fix what isn't broken.  If things are going smoothly with having both dogs crated...don't change it. 
 
As an example.....I have a Rott named Toby.  When he turned three years old I left him out of the crate and gave him some freedom while I wasn't home.  Three days into having more freedom he marked the wall.  I then decided this wasn't a good idea, and wanted to go back to the crating.  I put him back in his crate and he freaked out.  I wasn't sure why, but he started barking, pawing, and biting the crate. It took me almost three months to get things back to normal. 
 
I managed to ruin my calm, happy household, and there wasn't even a problem to begin with.
 
If I were you, and things are going OK now, I would leave it alone.

YES! We are in the same position.. Bailey (3 years old) has free roam of the house- never was a chewer, never touched his food (we used to free feed), and really never left our office window. Comet, who's a year a half, loves to tear apart pillows when we leave so he's crated- the crate is a Great Dane size and he is fine in it- which is also in the office, by the window. He goes in happily and it's peace of mind for us to know he won't be eating a pillow (and zipper etc)..
 
Good Luck!

Our six month old pup is crated while Dakotah gets free roaming of the house. Doesn't seem to be a problem.

Roscoe has free roam at night, and our new dog Bella has to be crated 'til we determine if she's trustworthy. It doesn't seem to bother them.  Both of them are crated during the day, though, 'cause for some reason Roscoe isn't trustworthy during daylight. [&:]

I used to have one dog crated, and the other not. When Max was upstairs, it only ever caused a problem when he first went in the crate, in fact, that was the only problem we had once I moved him downstairs really. Millie would bark when she heard his crate door closing, or when they were on the same floor, when she saw it. This would in turn cause Max to bark and start attacking his crate door while I tried to close it. So, I stopped putting him in the crate. They are both on different floors of the house though. Max is in the basement, and Millie is on the main floor, or upstairs. Millie doesn't destroy anything, but sometimes poops on the floor. It doesn't matter whether or not someone is home. Max is totally trustworthy uncrated when I leave the house, but if I am home and leave him in the basement by himself, he's not always. He will whine and bark if he knows I am home until I come back, but he is quiet when I leave, and he just sleeps. If I leave my bedroom door open, he will go in and tear up my pillows. So, I put a chain lock on the outside of my door and I lock it when I am not in the room. As long as he can't get in there, nothing is destroyed. He has never had an accident either, so I guess it works out ok. Still, I would be happier with him crated, because if someone had to enter the house, I know he would attack (actually, both dogs would). I'm, working on it though. 

One of my dogs is allowed free run of the house, one is in an xpen, on is in a crate.  Dogs don't seem to mind.

Kaiser has his very own room that he roams free in, and i put wyatt's crate in kaiser's room. When i kept Wyatt in my room in his crate, he would cry all day. I guess somehow they keep each other entertained in there.

Anyone have one of their dogs crated while the other is left out?

Sure do. No problems that I can see.

Yup, that's the way it is here--I did not crate train Misty, she's confined to the kitchen/family room when we are out.  Teddy came to us crate trained, so he goes into his crate in the family room, with the door pointed at where Misty sleeps on her pillow when we are gone.  When he first came here we had his crate in the kitchen, and he howled and carried on.  When we moved it to where he could see Misty, he settled right down.