I was also a little shocked but very flattered to receive an invite to come play in the next division up. I think it would be a great experience to play with some of the higher calibre players I would find there. I am, however very new to darts and think I need to learn a bit more, and pay my dues a little. I will be staying in 'C' to co-captain a team of the people who got me into playing darts in the first place. Moving up can hopefully be something I can look at next season.
In the meantime, here is a quick article I wrote on Darts Practice. I can not stress enough how important that constructive, non-stressful practice can be for improving your darts game!