"To be in a pickle" means to be in a difficult situation, from which one is unlikely to escape.
It's an American expression which comes from baseball slang for a baserunner caught between bases, or in a rundown. If the runner is caught in a rundown and is likely to be tagged out, no matter which direction he runs, he's said to be "in a pickle."
I think that it's a great expression and it's not old-fashioned.
I use it very often.
The expression is rather older than that: In a pickle
"Eventually distributors of intelligent, dark, and frequently intense movies were finding themselves in -- what do you know? -- exactly the same pickle we are today."
Salon.com, today