Hopefully there will be no difference to how the site looks or works in any way. If there is, something went horribly wrong!
Just in case anyone is interested in the gritty details, the site is being moved to a new server which gives us a bit more memory and more disk space, and more burstable processing power, so it might be a little quicker. The current server is due to be decommissioned as it's hit 5 years old and the hosting company doesn't like running old kit even though it's been very reliable; if anyone is ever in need of a good VPS provider I can happily recommend them:
http://www.bigwetfish.co.uk .