Well, from May anyway.
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/671818/mot-inspection-manual-for-classes-3-4-5-and-7-from-20-may-2018-draft.pdf
Just a draft for now, but don't expect anything to really change. Highlights that actually affect us lot as enthusiasts:
- No more changing steering wheels for non-airbag ones. The old rule of modified cars being exempt has been updated, and specifically states that "a car fitted with rally style seats, body kit and a sports steering wheel would not be exempt". So that's a shame, unless you really want to strip your entire car just to pass MOT You could just swap the OEM wheel back in, obvs.
- Defects are now Minor, Major and Dangerous. You can have as many minors as you like. Major and Dangerous are insta-fails.
- Low brake fluid can now be a Major (so a fail). Needs to be "substantially" below though.
- Low pad indicator lit is a Major (even if the pad has loads of meat left!).
- Sticking stuff to your windscreen rules seem to have changed. Outside of the swept area put what you like, as long as it doesn't "materially affect the view".
- It's now specifically forbidden to fit HIDs to non-HID cars Well, unless you fit an entire approved headlight unit (so a transplant from an OEM HID-equipped car).
- Sadly they've still not banned stretched tyres, however they are now mentioned and will be checked more closely for damage.
- Exhaust noise test is as per the current doc, i.e. can't be obviously louder than a standard car.
- CEL on is now a Major.
Now some of those may be applicable on the current test: I've cross-checked as best I can, but even I'm not infallible! Everything else is as you would expect really, these were the only things that jumped out at me as being a PITA. And of course some folks still have friendly MOT testers, so all this is just FYI.