Can Sony sell more than 140million Playstation 3 units?

At least that is their plan.

The original Playstation sold about 104million units world wide.
The Playstation 2 beat the sales of PSone, and recently tipped 140million unit sold world wide (wow!).

People are sceptic that Sony will be able to outsell the PS2. PS2 was the leading console of it's generation, and neither Xbox nor the GameCube could rival it.
So far PS3 sales are lower worldwide than Xbox360, and the Nintendo Wii has a solid lead.

But, Sony says that they plan for the PS3 to be around for 9 more years, and they expect a lot of PS2 users to go over to PS3 eventually.
Their plan is to reach 150 million sold units.
-H

Source: http://www.xbitlabs.com/news/multimedia/display/20080721215910_Sony_Plans_to_Sell_150_Million_PlayStation_3_Game_Consoles.html