I converted a lot of .cfm stuff to .asp while I worked at Intel. I think the reasoning was that ASP was less expensive (if your on IIS servers you basically have it supported) where as coldfusion has an extra cost and isn't quite as robust a development environment.
From a commercial standpoint cold fusion skill is also less common and less valuable in the marketplace. Over the long haul it seems unlikely that cold fusion will last against the might of MS and the low/no cost of Linux/Apache/PHP/MySQL.
If you want to eventually join corporate america knowing .asp will go a long way towards getting a job a "big time company" but the open source products are catching on with big corporations and have caught upto MS in just a couple years. Apache is the most used server on the web and as such it helps PHP and MySQL have a huge reach.
Performance wise it's amazing how fast, reliable and robust PHP/MySQL is. Lots of benchmark sites list it as faster than anything else for a lot of purposes.
I have used all three and PHP is easier than the other two to learn and use. ASP is very easy to learn if you can write VB and HTML but PHP has a speed advantage because of the way it is called. The convenience of form fields autromgically becoming variables in a PHP document makes it easy to use.
Here is a little form I made a while back when I was first getting into PHP.
amortizationNo DB, but great dynamic page generation and calculation possibilities. You also can build dynamic images with it which is very cool for charts and graphs.
I highly reccomend PHP for newbies and programmers alike and I wouldn't be surprised if PHP caught ASP as a sought after skill with corporate america. never discount MS though, .NET seems pretty formidable from my limited understanding.
Hoopster