Some interesting posts to investigate, especially the work on the Trend Strength Indicator. I've penciled in some analysis comparing the uses/ benefits of this compared to the TVA. http://cssanalytics.wordpress.com/2010/06/29/trend-strength-index-tsi-results-summary/
Another interesting post from CXO. From my experience I'd agree entirely with these findings, but would be interesting to see a similar study over a different time frame. The study found that those brokerage clients stating they were doing it for "speculation" dramatically underperformed those in it for capital growth.
Post 2000 wasn't exactly kind to speculators! However, I think the same study in different markets/ time frames would throw up similar is less pronounced results.
Certain mirrors performance in my own trading/ investment journey anyway as I change my outlook.