The reason I quoted 2800 for the Yew next to my village church is that inside the church they have a certificate from some tree association or other certifying it's "not less than" that age and signed by David Bellamy. I presume there are a lot of such certificates.
IF that's right I'd say the tree is looking chipper and is likely to last quite a while longer yet.

I did some looking around a while back and there seemed to be an awful lot of definite bronze age site/yew tree connections, irrespective of churches. Life's too short to make it worth me doing the research again though (or, "can't be arsed" as we say in Stourport!...)