What I think is that it won't improve it enough to be useful.
Either you are a teacher who believes that practical has an important place in science teaching and learning. That allowing students to experience investigations and make discoveries in an authentic way is valuable to the development of students understanding. Or you are in a position where practical work is not, well, practical for whatever reason.
Either you are going to do practical work because of its value. Or you are not. And if, as I suspect, you are not going to be moderated every year then either you are going to do practical work because you feel it is valuable or you are going to do just enough to cover your backside just in case.* You will find a way that involves the least amount of effort (this is not about laziness) and tick the boxes. My conclusion from this is that there is little value in the pass/fail addition to GCSE science.
A far better way to encourage practical work in science, if indeed that is what we want is to create a curriculum that lends itself to valuable practical work. (When I say 'we' I mean the exam boards as the curriculum is now in place).
In the specification I follow too many of the suggested activities don't actually teach the specification statements. Why on Earth am I going to take time out of a busy teaching curriculum to teach something that isn't actually going to be examined and might actually distract my students? We'll observe refraction because they need to know about it, we'll look at the relationship between wire length and resistance because it is explicitly written about in the specification. If I am teaching about stars I am not going to make a telescope unless it is important that my students know the composition of a telescope. (They don't in Gateway). I am not going to get the whole class to create wind turbines if my one demonstration will be sufficient.
When we moved to the current specification styles on 2006, I hated it. I hated it for exactly this reason. Bitty, incoherent and no time to go into detail before you moved on. Don't get static electricity? Never mind we're studying half lives now. Practical work was often irrelevant, particularly in core science. (I think I do one class practical in the whole of P2). By the time we get to additional science students are not interested in getting out of their seats in lessons.
If we return to a curriculum where we can teach topics together and the specification builds from simple ideas to those that are more complex we can start to use practical activities more in our teaching. I don't like to run a lesson on sun cream resistance into a lesson on ultrasound to make space for an investigation. However, I would be more inclined to do that if the topics were related.
When I taught pre-2006 AQA specification I was able to decide which statements went in each lesson. In the post-2006 OCR Gateway specifications that has not been practical to do.** If the new specifications allow more flexibility (and because they are terminal they should) then more practical work and more importantly more valuable practical work will be able to be carried out. I am actually quite excited about this.
So lets use the curriculum to encourage practical work, lets give time to teachers to teach students about 'how science works' and lets accept that good teachers need less constraints to do a good job and poor teachers will find ways around them.
*Something that sticks in my memory is an OCR IAU examiner telling a group on a course he was leading that there were many schools whom never allowed the students to do their own practical work in the data task and gave every child the fall back data. There are schools out there doing everything they can to make practical assessment as straight forward as possible for themselves. In a way I can't blame them, it is an administrative nightmare and we should be trying to cut this for teachers wherever possible.
**Partly because both the schools I have taught it at have 70 minute lessons, and I found that 50 minute lessons mean pace in lessons is high, but there is more time to stop and consolidate at a latter date. And partly because the specification is split into 8 sections per module, and each section should take a week to teach.