I don't think New Zealand will be as vulnerable as South Africa were against the Netherlands and if they win it will make the next two matches in that group knockouts! And fingers crossed for today's game
You are almost right
If New Zealand win then it is definitely a Knock out for England since if they win they can't qualify and it become SA and then the winner of the NZ v SL match.
If England win however then it becomes a touch more interesting as there will be 4 teams on 4 points. Only problem for SA is that they will have no more games meaning their chances of going through are slim but not none.
If Eng and NZ win tomorrow then for SA to go through Eng have to lose to Netherlands and SA need to have a higher NRR than Eng and the team which loses between NZ & SL.
The problem is that both NZ and SL have a higher NRR than SA at the moment which means that the most likely scenario for them to go through without beating England is to lose the Eng match closely (by like 1 run or 1 ball) and then have Netherlands beat England and the SL to thump NZ.
Its not impossible, just improbable.
On the other hand if the Dutch beat NZ tomorrow well then the group is thrown wide open as there is a possibility of all 5 teams ending on 4 points (if netherlands also beat Eng, Eng beat SA and NZ beat SL).
Here are all the possibilities left in this group:
The bolded bits first are Saturday's results.
NZ & SA win:
Eng & Netherlands are out
SA are through and are joined by winner of NZ v SL
NZ & Eng win:
Netherlands are out.
Winner of NZ v SL goes through.
If Eng beat Netherlands they go through too.
If they lose then the highest NRR between SA, Eng & the loser of NZ v SL goes through
Netherlands & SA win:
SA are through.
If SL beat NZ they are through.
If SL lose to NZ then the highest NRR between SL, NZ and the winner of Eng v Netherlands goes through
Netherlands & Eng win:
If both Eng and SL lose then its a 5 way tie and the 2 highest NRR goes through
If Eng win and SL lose:
Eng are through
Highest NRR between NZ, SL and SA goes through.
If SL win and Eng lose:
SL are through
Highest NRR between Eng, SA and Netherlands goes through
IF both SL and Eng win:
Eng and SL go through
I think that pretty much covers all the possibilites assuming that there is a result in every match. If any match is rained off then through this out the window