Well with only a few days to go before the announcement I am going to put my tuppence worth in.
I am going for an SECR 0-4-4T Class H to go with the birdcage stock. It will fit in nicely with their growing range of SECR locomotives Bachmann produce.
I think an LNER C1 is on the cards - they are virtually identical to the LBSCR Marsh Atlantic which they were going to produce announced last Sept and will also tie in nicely with their NRM range. I am guessing they could do a special NRM only model of a C2 (Henry Oakley) using the chassis of this model at a later date.
After this the crystal ball goes hazy so I am going to have a guess of an NBR Class C or LNER J36. 0-6-0 Freight engines are in vogue with both Bachmann and Hornby. As Bachmann have already announced they have dropped proposals for a J15 as Hornby have announced theirs, would they see this as an alternative? A Scottish loco, to possibly go with the D11/2 "Scottish Directors" they already produce and also it ties in nicely with the anniversary of WW1 - plus "Maude" is preserved and currently at the NRM.
I doubt there will be any carriage stock announced as there was many announced last year.