Found a story about some Chinese company ripping off Blade & Soul already.
http://news.mmosite.com/content/a/2012-03-15/blade_and_soul_got_ripped_off.shtml
A case of two games with similar themes yet radically different gameplay sharing the same name. I couldn't help but notice that the 'other' Blade & Soul is made by a Chinese company.
Good luck issuing C&Ds, NCSoft. You'll need it; China is notorious for not giving a flip about copyright and trademark law, even their own.
Fact: You cannot copyright a title. You CAN trademark it, but you cannot copyright it. If NCSoft did not trademark the title "Blade and Soul" before the Chinese company announced their game, too bad for them.
Was that trademark? I thought I read that was Whedon (who grew up in England and has referred fondly to the Avengers TV show in interviews) trying to avoid confusion, especially after the stinker of an adaptation of that back in the 90s.
You can trademark a word, logo, phrase, design, or combination of these things. If you only TM the word other companies can still use it as long as it won't confuse the curent customer base; in other words it would have to be a different type of business or if it is a similar business type you must TM the words as a logotype so as not to confuse customers for the other business.
That said, if we drasitcally change what Avengers is and make a different styalized logotype for it we can use it. Most people just avoid using anything which might cause undue stress, legal disputes and negative press though.