I am suprised they didn't try at least doing only the national part - with the regional part cut.
I'd argue that they should have cut the national part and supplied the UK news video and scripts to the regional centres.
Let them put out the bulletins in a similar fashion to radio news bulletins where there is a mix of local and national stuff.
To my knowledge, all of the regional centres can access the footage and rushes so in theory they could do this already.
Certainly when Birmingham did news updates after The One Show in 2006 they would sometimes do the National and Regional headlines. I believe that was a 4 week pilot that lead to the 2007 pilot of the 8pm bulletin.
I just think the rationale for it existing isn't there any more because of Social Media, the presence of online news outlets and the target audience moving into new avenues to their news and current affairs.
Oh it's such a perfect day, I'm glad I spent it with you...