I should think it is respected, and to be fair having studied at a redbrick the degree system is not very different, in fact it may be worse and I think employers should take open university degrees as some of the top degrees you can attain, i'm sure over time the courses available will increase (in fact they may have done considering the threads OP date) and more tie in with the big physical universities have occured.
Aside from having the occasional opportunity to talk to a professor in person you have exactly the same resources etc. For University today you spend 9000 £ + to buy your own books, support yourself financially entirely (remember those are your loans, not free grants) motivate yourself and study in your own time frame with your own resources in your own space.
Your essentially paying for the reputation of the university. As exemplified by The University of Birmingham cutting its departments and staff to artificially inflate it's results and so attain the smarter and more self-motivated students that require less interaction (which is good when you have just cut staff) and so on and so forth in a cycle and then trumpet it's "university of the year" badge as if people cannot see though its thin veneer.
All the while making a £20 million + surplus and having the highest paid chancellor in the country (and having fees up to 16K+ in the pipeline to make even more money, despite en masse protest and resignments).
An open university degree will be done in almost exactly the same method but requires the person to work slightly harder as you lack physical contact, but aside from not being sat in the room when the lecture is being taught.
There is no difference and no reason for an employer to think of it as less particularly with non-contact heavy courses, in fact I'd say its worth more, especially as the available online resources far outweigh anything any top uni has to offer (you can even access other unis materials), internet learning is where most of the big universities are going anyway (JSTOR, Online lecture recordings, Online learning centers and course portals (all of which means you can get away with employing less staff of lower quality to make even more money).
Remember Modern university is like modern gaming: pay to win, it's a business for profit now and you are deluded if you think that is not the case.