What's the difference between the English client versions?

When I go to download the Diablo III game client from Battle.net, I have a choice between three different clients if I intend to play in English: English (US), English (EU), and English (SG).

• I know that it's not determining which servers I can access, because there's a "Global Play" concept, which means everyone can play on whichever server they want.

• I know the client is not used to determine the "home" region either, because the "Global Play" page also says that:

  players will create characters and play in their "home" region, which is determined by where they live (specifically, the country of residence registered to their Battle.net account)

So, what is the difference between the clients? Which should I install?

Overall, there's not going to be much difference. It will boil down to things like:

• different EULA
• different pre-selected Server (EU for EU and Americas for US)
• links in the game leading to different websites (e.g. http://eu.battle.net/d3/en/ instead of http://us.battle.net/d3/en/ )
• "information window" on the title screen (like it exists in SC2 and WoW) will probably receive the displayed text from different servers.

And things like that. Furthermore, it's probably an easy tool for Blizzard to dispatch region-specific changes to a certain client only. E.g. the European Union introduces some crazy law that forbids the use of roman numericals, then Blizzard could patch only the EU version and replace all the III with 3s.