By all accounts its was UNITE that initiated this latest round of talks, not BA. From that it is reasonable to conclude that UNITE feel more pressure (for whatever reason) to settle this dispute.
BA has already signalled that it is willing to return ST, albeit with restrictions on the effective date of joining. UNITE (TW) have stated that the last deal was acceptable with the exception of ST and the disciplinary issues.
It is again reasonable to conclude a few things from this. The main parts of the deal are unlikely to be significantly different from the last deal. The areas of negotiation are likely to be over ST and disciplinary issues. it is also likely that UNITE would wish to secure bargaining rights for MF and perhaps some mechanism to gain some input into route transfer to MF.
I believe that ST will be returned with a phased return of date of joining. I think that there may well be an independent review of the disciplinary system perhaps done by ACAS, but I see no way back for those sacked recently. I think UNITE may secure negotiating rights for MF and the right to be consulted over route transfers. There may be some other sweeteners in the deal from BA but they will be tied up in a no strike deal for a number of years. I suspect there will also be a clause that includes some loss of ST and or other things should there be a strike in the future.
It will be interesting to see what the deal is as it will define industrial relations for the next several years.