OFF TOPIC SEO type question

I have been thinking this little quandary of mine over for a few months now. I thought I’d throw it open to the community as a general discussion, I might learn something and so might others in the same sort of situation. It may make some interesting chatter?

Here is the background:

I have a business website started early 2009, it was a bit of a punt at the time but it is moving along nicely now. Not really thinking it over I plumed for using a area specific domain extension. (not the real site of course but I am avoiding making this an advert).

At the time I expected to be trading mainly in the UK so didn’t really bother considering any other options.

Since then my business has developed and gained direction in a specialty and more importantly a customer base. Using my key words it ranks usually on Googles top listings.

As it happens I have acquired customers all over Europe and a few in the likes of Brazil and Australia.

Along the way I have managed to pick up a few other alternative domain name which are more specific to my branding and specialty. I have also picked up the .net version of my current domain name.

Here is the question:

Baring in mind any SEO issues do I opt to change my domain to either the more global .net brand name or even more radically change brand names altogether to reflect the specialized nature of my product range.

The plus side is more readily identifiable branding, the down side is destroying the current search engine status and any back linking. At the moment I have the alternative brand name on a framed redirection to show the new domain in the address bar to anyone using that url.

Change domain names or not!

What would you do?