First, as you can see from the photo, there will indeed be a wedding for Sian and Sophie. The girls have matching strapless fluffy dresses which look quite pretty. But, with Sophie's growing attraction to Amber after their one drunken kiss the other week, we don't know yet if the wedding will go through. Seeing as Sascha Parkinson is leaving, there's a good possibility it won't or won't be a very long marraige if it does.
Edited to add: There's more information here on the Daily Mail with more pics too. They reckon Sian will leave Sophie at the altar when she finds out about Amber.
There's also more news on the Sally and Frank speculation that we brought to the table the other day. It says here that Frank and Sally will share a kiss under the mistletoe. Sally and Frank grow closer after her recent breakup with Jeff and as we all know, Sally's head gets turned quite easily by someone with a bit of power. I still think she'll end up being instrumental in helping Carla's case against Frank and end up humiliated as usual, having to admit she was wrong. I wonder if she'll go crawling back to Carla for her job back?
See also: Where to buy Sophie and Sian's wedding dresses