As far as Toyota, I have owned 2 Camrys and been very pleased with the fit and finish, maintenance (or lack thereof) experienced, and the long term of the cars remaining good transportation and mechanically sound. We purchased a 1983 and a 1988 and kept both 16 years each in snowy Alaska.
Partly because of our experiences and also because of the technology leap which the 2004 Prius signified, we purchased one and took delivery in December 2003. I enjoy driving it and can't wait to take it on longer trips where I can evaluate it over a longer period. The integration of the technology is impressive and I believe we will be seeing many more car makers trying to catch up in the next few years.
My experience is similar to "FarNorth", except we live in Phoenix, where summers get up to 115 degrees (with a few days near 120). GM, Ford, Toyota and maybe others have test tracks here because of the heat and dust.
My wife and I bought a Camry in 1998, and a classic Prius in 2002. Both have performed very well with no problems at all, and they have had only routine maintenance and tires. (You have probably seen posts on the OEM Bridgestones that came on the classic Prius. I've got Michelin HydroEdges, now - a great tire.)
I am sure you will hear mostly good things about both Toyota autos in general, and the Prius. Most drivers will tell you that they would buy another one; not so with numerous other makes and models.
As a matter of fact, it would be interesting to know how many 2004 Prius owners previously owned the classic Prius. I'll bet the percentage is really high, considering that their classic probably had many, many years of life left in them.