We have a .co.uk version of our webhosting site. (the company I work for) The co.uk really only changes the prices to Pounds, thats about the only difference.

I think it's best to use different designs for different domains, even if you are the same company. For something like this (in the first post), it could be expensive. The reason you're doing this however I fail to see the point.

You say you're getting a design done for each region bcause of currencies and language, but why when you could easy have a backend scripted that detects their geographical location and directs them to that site within yours? You can offer it in almost any language, as long as you provide the text to the programmers, or simply using a seperate script that converts it, thus allowing you to enter your data in only once, and not have to re-write in German, French, Spanish, Romanian etc.

Right now, we only use .co.uk domains, but we do international work. We quote in both Great British Pounds and their native currency. I think the main reason to use seperate domains and designs is because of your target area. For example, a British citizen may consider your site 'crap', but to a Romanian it could be 'amazing', style differenciates throughout regions, and all depends on target areas.

You may also find that you can offer some services and / or products to citizens in one region, but not to the other. This being another reason to use seperate sites. There are of course multiple other reasons, but the sole reason of language changes and / or currencies is not practical nor sensible in my opinion.