I put this in the Bordeaux thread but in case anybody missed it.

Keep an eye on your emails right up until departure. I was notified at 19:15 last night that my train tomorrow was cancelled. Luckily I came across it yesterday evening when pulling some info together for France, but all the helpdesk phone lines were closed by the time I did. Got a day off today and managed to get through to Eurostar this morning to change it, but won't know about our train coming home until we're in France.

The information SNCF send you is quite crap and mostly in French. Hopefully most trains are running or people will be be moved easily enough - mine arrives 10 minutes later so no drama in the end. Probably just best to keep an eye out though, particularly in the 24 hours before you go/travel whilst the strike is on. Good luck everybody.