Something I have found (on several occasions actually!) that might be a good thing to note in the article: some of the idler and tensioner bearings were shipped dry and noisy from the OEM manufacturer to Toyota. I doubt Toyota even boxes these parts; they just flow through the parts pipeline. They destroy themselves fairly rapidly.

A simple way to check your replacements: spin them. If they make any audible noise, get a different (silent) one from the dealer. Personally I would always replace the idler and tensioner as well as the water pump when doing a timing belt; its just cheap insurance.

OK, not that cheap, but a real timesaver.