Someone asked me this the other day and I thought it was an interesting dilema.
Take a lifespan of the refurb at 7-10 years and the fact that cabling again after doing this would be a nuisance (though not impossible), would you take the opportunity to go for a fibre run around the building to strategic points where you can access the cables, even if you didn't need or use the fibre immediately?
I remember an office re-fit we did in 1993 and had a 10-base-2 network (or whatever that old coaxial based 2mb system was called). We thought it would be plenty at the time. The downside we discovered later (we were badly advised) was not so much speed, but that we couldn't use the cable for a subsequent PBX that was installed in 1995. Data and telephones tend to use CAT V. It's the "universal" cable of today, but what will be the "universal" cable of tomorrow?
Some considerations I guess would include things like "Does fibre date?" - i.e. are there different types of fibre optic cables, or are they all based on a standard likely to last the next 10 years?
I can see a time when all data, telephony and video is run over fibre. I'm just not exactly sure when that's likely to be.
I don't have this dilema by the way. My office is small and cabling here is easy so we can do it as and when. I just thought it was an interesting question.