There is a team in Denmark, working on building body and face models from persons genetic code. Stuff like age, height range, skin, hair, eye color, big/small/regular nose, wide/narrow face.
However, telomeres are repetitive code, and not amenable to standard PCR and sequencing methods (as far as I know). I don't know if the amounts of DNA or chromosomes typical in forensic samples are enough for the techniques used to measure telomere length. Well maybe they are, if the Danish group is working on this.
This is not a case like CNV (copy number variation) where a whole gene can appear a number of times, so I think this is somewhat possible by PCR (though probably not very precise).
How?
If the repeated sequence is longer than the chunk you have no hope of knowing how many times it repeats, if on the other hand it's much shorter (I think it's 6 bases for telomeres) you can see a good number of repetitions per chunk.
If you want to know something more detailed about sequencing and CNV I can send you a couple of sections from my PhD dissertation.