Based on the capital markets day presentation, Finnair is likely to have a completely new business class for the A350. E.g. modern Cirrus seats.
If that's true, I really welcome the change!
Although not many years old, the current Finnair Business Class offering starts to lag behind, especially what come to the seat, as the competitors have quite rapidly improved their offerings. In all fairness, Finnair was probably a bit unfortunate with the timing of the previous upgrade as the rapid business class development was just starting when Finnair was forced to make the previous investment decision.
What I don't like in their current A330 Business Class:
(1) lack of privacy (no dividers between the seats, and seat&aisle)
(2) narrow seat and lack of room for your feet (you can't really have alternative sleeping positions and change between them)
(3) lack of storage space in the seats
(4) seat materials: the light blue fabric looks quite 90s'
(5) the upgrades from coach. It is probably incorrect to say this out, but I don't really like the operational upgrades that they seem provide for the coach passengers. As Business Class is Finnair's most premium product, I wished there would be some respect for passengers flying with full fare tickets. Because Finnair has very limited crew serving the business class, the extra passengers drew attention from real business class passengers when the cabin gets fuller, create hassle, and in my opinion, degrade the overall experience
(6) meals: fortunately, full-fare passengers seem to get seating on the first rows (1-4) where the serving starts, but I really hate it when your choice of meal runs out -- it should never happen in the premium class! In the end, I also pay for the opportunity to get to choose the meal, and feel that Finnair should be prepared to carry the extra weight and pay for cost of the meals that are not eaten. Furthermore, I don't either appreciate the pre-ordering concept. I like to select the meal in the plane, on the spot, depending on the mood / feel at the time. Meals themselves: not great, but ok
(6) Boarding. Priority boarding should be enforced. On some stations it never seems to work (e.g. JFK). I was there on Thursday, and it was a chaos, just like all other times. Somebody, please take an action of this!
I think that the new business class will fix bullet points 1-4 from the top. Others could be fixed with little/no investment.
What I wish they kept / what I like:
(1) the superior service. The 40-60 year Finnish ladies are probably the friendliest persons in the airline industry when you treat them with respect. I mean, they take good care of you, even from your special wishes. Keep them, they try hard to please you!
(2) IFE: don't invest in the systems that will get outdated in 2-4 years. You can have a screen for iPad, but please, don't spend your little money on the IFE. Save it for something else!
(3) The wines, beverages: good, but could you please make sure that you always have availability of the most basic items like Diet Coke (which I order -- too often you are out of it

(4) Helsinki airport: super nice, super fast. Keep it!
Does this correspond your view?