I see it coming. Soon Cramer is gonna hype this sector. With increasing Diesel prices making Trucks less cost effective over time and Railroad transport more efficient in terms of pounds of merchandise per gallon of diesel transported over a mile and rails being revitalized I see it coming. Start looking at Rail Transport folks.
It's difficult to fade Warren and his "coal-play" in Burlington Northern, but if the economy is in the process of "tanking" this should not be good for the rails, at all. As it is, 2007 was not a great year for them statistically speaking in regards to carloads, traffic, etc. And that is a year where GDP was pretty solid up until Q4.
Looking at the earnings of the 4 major US rails there's been a continual uptrend in EPS over the last few years. The sector as a whole is still quite cheap compared to many others out there...you want something over-valued that will be affected from a 'tanking' economy, look no further than the lodging industry.
Railroads have solid fundamentals and will continue so until oil gets cheap again (nowhere near, in the foreseeable future). Ask Warren Buffett. Will this solid fundamentals turn into a bubble? Only time would tell but we aren't there yet.