"By sharing your portable ID, other users will have access to your PlayStation®Network Online ID and may contact you over the PlayStation®Network."

 
 
UPDATE: I've found that I can compare my trophies to people who are not in my friends list, so surely this means that Giant Bomb should be able to access my trophies just as I can access anyone elses trophies, right? 
 
You also don't have to be signed in to PSN to see these trophies. Which leads me even further to believe that they will be able to add them. For example, here is a link to my trophies: http://profiles.us.playstation.com/playstation/psn/visit/profiles/Tebbit    

They have not said that they have an API available now, so it will probably not lead to trophy support on Giant Bomb. However, Microsoft are very quiet about their API, they don't like to shout about it, so perhaps Sony have implemented an API, and are being quiet about it, like microsoft.

"Well thats all very site specific, and it's Sony's own API so they can obviously use it.  If they don't want other sites to use it though, then they won't publicilly release it... "

Lol I can't really API's...Imagining the Sony one, it would be information the site has, linked directly to the PSN, so that things like tropheys, friends, login times etc can be linked to websites with up to the minute updates...if you get me.  Basically everything the official Sony site does now uses the PSN's API, but seen as Sony won't let other sites use it, they can't do everything that the official site does.

I'm sure it's something the GiantBomb guys are keeping a very close eye on. The reassuring thing is that Sony seem interested in building on the trophy system so if we, as the Playstation community, make enough noise about an API, I'm sure they'll develop one.