I'm in a similar situation, my Class 1 has just lapsed in October. Looking at the Medical section on the CAA website
http://www.caa.co.uk/srg/med/default.asp a Class 2 is valid for 5 years from date of issue
dependant on age . Seeing as you only get a Class 2 from the date that your Class 1 expires I would imagine that Whirlybird is absolutely right, we should now have 5 years in which to reval our medicals so long as we are within the age bracket (i.e. pre-30yo).
If you are over 30 you have to reval your class 2 every two years however. Most of this is on the CAA website although it does fail to answer the very fundamental question that we want answered! Thank god for PPrune! If you do want to reval soon though, the CAA website does have a directory of local AME's who can do it for you which could save some time (on hold to the CAA!)
If you do get any other info, be keen to know...
FJ2k