Train Companies are now gradually confirming their plans for their respective strike days-
the LNER, Anglia (including Stansted Express) and South Western Railway timetables are now confirmed and tickets on sale,
c2c, LNWR, Chiltern, Northern Rail and Transpennine confirm no service at all will be provided.
Southern will only run a Gatwick Shuttle, Thameslink will only run a St Pancras to Luton airport and a Kings Cross to Cambridge Shuttle. No Great Northern service will run.
Great Western are still to confirm.
EDIT- Avanti have now confirmed that no trains will run on their strike day- 3 February.
Important note that Great Western on Sunday 4 February (a non strike day) will run no long distance services between London Paddington and Bristol, South Wales and Exeter/Plymouth/Penzance, due to the overtime ban. See their web site for the lines that will run LIMITED services- https://www.gwr.com/strike
LNWR also expect major disruption that day and Chiltern will run NO service that day.