What are the implications of the whole class failing an exam? I am an MSc student and in my class are 10 people. 
The module has been taught exceptionally poorly and as a result none of us can see ourselves passing the module. The exam is in two days time. 
By failing the exam we will have to retake it in the summer because we will not met the threshold to pass the module. 

The lecturer mentioned that the department was thinking of scrapping this module so this may be the last time it is run. Also throughout the module we got the impression the lecturer was really concerned about us and we got the impression people have done really badly in this module in previous years to cause him concern. Talking to other lecturers in private, have supported the fact that this professor is very bad and has not taught the module well enough to prepare us for the exam. 

In the open book homework assignments, the class average has been high, around the 60%-70% region. But these assignments in total only account for 20% of the final module grade. 
The final exam accounts for 80% of the final grade. 

What are the implications, if any, for the lecturer or the university if everyone in the class fails the final exam? 

I am in the UK.
Your question is about the consequences for the lecturer, but you've asked in comments what you should do.

In the UK, if it's felt that noone has reached the required standard then noone will pass. The basic paradigm is that everyone is measure against a standard, unlike in North America where it's more about measuring students against the others in the class. Still, it would not be a popular move to fail a whole class. What the effect on the lecturer would be will depend on their position, and what the uni is like.

Given it's two days from the exam, and I'm guessing it's in maths or similar, I think you should start memorising. The pass mark is 40% (usually), and with high homework scores you can pass with slightly less than that. You're more likely to convince someone you deserve to pass if you can show you've understood the basic ideas of the topic. Make sure you can reproduce the key definitions and theorems, and have at least an intuitive understanding on the methods of proof appropriate to what you are doing.