Paul Heydon, of independent banking firm Avista Partners, had a presentation at the Edinburgh Interactive Festival called Disruption = Value Creation in Games. These are just the slides.

Among them was this graph, which represents his estimation of various entities market cap in the video gaming industry.

Nintendo - $34,959m
Other PC/Console (w/out Nintendo) - $33,223m
Online - $23,457m
Mobile - $8,257m
Retail - $3,110m
Payment Services - $1,368m
Distribution/Accessories - $311m
Outsourcing - $255m

He does not include independent developers and small private publishers. Online includes MMOs and Internet social/casual games.

From MCVUK.

Market cap numbers don't tell me much. I'm a revenue guy.

I agree with him!!

{pssst we are just bitter PS3 and 360 didn't get a specific mention}

Go Nintendo!