For what this is worth, TB is a bit off for Neptune and way off for Pluto.

I don't know how long it would take an ion probe to reach Voyager 1's current position, but a solar sail could do it in 5 years with constant acceleration.

Regarding the Pioneer Anomaly, I am still wondering if it has a "conventional" answer, but as scientists continue to scrutinize the data it seems more theories keep falling by the wayside.

For example, here is a link to two recent papers on how the outer realms of the Sol system may not contain any really large bodies:

http://SkyandTelescope.com/news/article_1609_1.asp

Of course the verdict is not in yet, but I am glad to see that it not being ignored, either. Maybe someone's working on a HUGE Dyson Shell way out past Pluto and the Pioneers picked up on its mass.

Or maybe something's passing through our neck of the galaxy for a visit.