Hi Anotherglass
I am a very old Mum (Past 40) with two DDs in Y2 and Y4 respectively, and they also have videos to support their teaching - also quite a bit of whiteboard work.
I think there are several things changing for our children here.
An adult talking at them all day seems incredibly boring to today's kids.
They are used to fast paced tv/ video games/ etc...
They are the multi-media generation
At first I had your reaction - Oh my goodness they're just parking my kids in front of the t.v. But in fact it's not always like that. Yes, they're using resources to help underline the point they're trying to make - but sometimes the short-clips explaining the central point do it so well & visually (which really helps with maths) that it makes learning more straightforward and productive for everyone.
A lot of the 'DVDs' shown are in fact short clips which last less than 4-5 minutes. Some great examples for Primary maths are here: www.bbc.co.uk/learningzone/clips/primary/maths/
As ever it depends on the teacher - but anotherglass - I would talk to the teacher - you'll probably find that the school is signed up to on-line learning tools (education city/ espresso/ mymaths/ etc...) and that it is unlikely they are spending hours in front of DVDs - with the exception of when the entire class watches a movie (which usually includes writing exercises, whole class discussions & role play later).
So basically anotherglass - I think what you may need to realise is that things have moved on quite a bit since you were at school. And frankly some of the clips explaining grammar, geography, etc... off the BBC Learning 'BETA' website can explain a point far better than I ever could, so I wouldn't be against a teacher taking advantage of these useful teaching tools.