This year the Oxford English Dictionary has added new words and phrases to the dictionary.

Editor Jesse Sheidlower

"Our editors are currently going through the entire alphabet bit by bit, writing new entries and revising existing ones in order to stay current," "It's a massive job and will take years, if not decades, to complete - at which point we'll start over again."

One word that I would have thought was already in the dictionary was Internet. That word was just added this year. Up until then, it was not even in the dictionary and has been a household word for many years.

Other words and phrases added are:

Argh
Bikini wax
Central air conditioning
Chill pill
Club hopping
Comeback kid
Comparison shopper
Cow pie
Focus group
Glitch
Islamophobic
Low-maintenance
High-maintenance
Hollywood ending
prime directive
Problemo
Projectile vomiting
Scratch and sniff
Sleeper cell
Stop gap

The entire list of words and phrases added can be found here.

My question is should slang words such as problemo and phrases like chill pill be added to the dictionary or should they have a separate book for that?