I have 5 of my cels framed so far, and they're 
all out of the cel bags.

There's nothing worng with keeping them in their 
cel bags...but!

You may want to consider if the bags dirty...or 
has crinkles in it...holes...and there may be 
more of a glare factor if you leave it in the 
bag.  

If you are going to get it professionally 
framed...Get it done right...With acide free-
matting/backing, and UV protected glass.  The 
people should know if their supplies are acid 
free or not...and if they don't know...Then you 
need to go elsewhere^^;...

Also...When preserving cels there are many 
arguements about wether or not cel bags should be 
opened periodically to let gas escaping from the 
paint out.  Every so often I do an inventory of 
my cels and open every bag...air it out...and 
then seal it up again.  So...If you get it framed 
in the bag you may want to consider that little 
tidbit.  

Cel bags keep cels from most outside damge...and 
having it in a frame....to me...is just like 
having it in an expensive cel bag^^;!

So...It's up to you...But...From personal 
experience...

I'd leave it out of the cel bag.  Make sure the 
people you are dealing with know what they're 
doing.  MAKE SURE THEY'VE FRAMED ANIMATION CELS 
BEFORE!!!!  That is a biggie!  If they haven't 
there is a chance of them hurting your prizes in 
the frmaing process...We've all heard the horror 
stories of framers cutting cels up before 
O_O!!!!  Get the inside scoop on what they 
know...and have them take you through the framing 
process to see if you want ot subject your cels 
to some of the processes ^.^'!

Hope this helps!  Any other questions just ask!

PLUS...

I know the pic isn't the best...But here's 3 of 
my baby's framed!  I'm gonna try to get better 
pics this weekend^^'!