If something is going to come out, I am sure leaks are just around the corner for this week. However, some very solid sources are very much saying nothing is coming out this week. Lets see what is being said.
Please take these as rumors.
via an anonymous source on Faeit 212
To cut the rumours, GW won't have a new release this week and probably none before x-mas. They are hurrying up retailers with orders as GW closes up for holiday season and orders done past 16th won't arrive untill 2015. In this case I guess it is safe to say there are no suprises planned for now, at least not for store sales.
As for what is being discussed regarding the possibilities of new Necron models, here is a link showing warriors on a larger base, with some models that most people are saying are conversions. Also possibly a new Necron Lord.