With regards to Yularen: I doubt it.
You don't go from an Admiral to a Colonel (well usually - I suppose he could have changed service branches and not been as highly placed in Imperial Intelligence.)
But Navy ranks go Cmdr., Capt., Admiral - and the Empire has Grand Admirals.
Army Ranks go Mjr, Col Maj, Col, Mjr Gen, General - and maybe Grand Moff is above General in the Empire? Unless Tarkin came up the Navy ranks - I forgot.
About Yularen. I looked up the Clone Wars movie on Wookieepedia and I looked at the List of characters and I saw Yularen's name on the list. This means that he is definately an Admiral in the New Movie.
As usual, Tycho's source was spot-on. Can't wait to see the Wave 4 pieces his source mentions. If you watch this clip HERE (minor spoilers, I guess) there is a Separatist leader who looks possibly central to the plot and is featured prominently in an action scene. I wonder if this is this "Admiral Yualrin". He is near the end of the sequence.
EDIT: Here's a screen cap of the dude:
How does one go from Admiral to Colonel?
Darth Vader is becoming the Mickey Mouse of Star Wars.
"In Brooklyn, a castle, is where dwell I"
The use of a lightsaber does not make one a Jedi, it is the ability to not use it.