Hi Sean,
First off, depending on the domain, you should be able to check the IPS tag a number of ways. I'm presuming this is a .uk domain e.g. google.co.uk and as such, if you go to
Nominet UK and then look up the WHOIS info on the right hand side, you will be able to see the IPS tag and can see if it's been changed. Once it is changed, the eUK guys here should hopefully have everything up pretty quickly as it's just a matter of getting it set up correctly to point to the new server. Unfortunately until the people you were with make the change, there isn't much you can do. If you could give us the domain name, we may be able to help a bit more.
Regarding the migration, changing servers shouldn't really matter to google. I doubt you'll slip at all but I'm not an expert in Search Engine Optimization so someone else may be able to answer this second part better.
-----
After looking at your profile, I thought it may be a .com domain and you can get info about the nameservers etc. at
Whois.net. The one you have in your profile seems to be with a company b-one.nu still but I think this may be web site hosting 2?