Im going to the one in the 18th too and im just a tad excited aswell!
I think its just like the wedding show I went to there - lots of different brands/companies with stalls where you can buy/order stuff from with usually a discount on the day. plus they have well known people there like Super Nanny etc to talk to (I think)
Hiya, DH and I went to the one in London in Feb (?). We got some good discounts, quite a few freebies (samples) and probably as importantly, got lots of information on different products such travel systems, cots etc. As well as smaller businesses, there were bigger stalls from Mothercare, Mamas and Papas, Kiddicare and BabiesRus. We didn't catch any of the shows or classes but definitely would recommend going if just for all of the above. We went on the middle day as it was the most convenient for us but I have heard that if you go on the last day, you can pick up even better bargains as stalls want rid rather than having to take stock home. Would also suggest researching online for discount codes for tickets - think mothercare amongst others were offering 40% off. Hope you have fun!