[sergiotapia]

Same, it sounds off to me. I'm also not a grammar expert but know when something sounds 'off'.

"Nintendo Wii U is released." - it just sounds strange.

"Nintendo Wii U has been released." - ok, sounds good.

"Nintendo Wii U released." - ok, sounds good.

[jay-saint]

""Nintendo Wii U has been released."

has been is Passive voice and should be avoided.

[lobster_johnson]

Sometimes good advice, but certainly not a rule. As Pinker points out in "A Sense of Style", passive voice lets you modify word order to emphasize what's important to the reader.