Skip has a good post about using new vs. older technologies.
Technologies continue to change. Companies must change with them or can lose their competitive edge through obsolete technology. Technology shouldn't just change for change sake, but as needs change either internally or with your customer, you should find the latest technology that can provide a solution. However, your customer, organization, and perhaps even upper management may not understand the short term costs of moving to newer technologies. So, what are the advantages and disadvantages of legacy verses newer technologies?
Technologies are like any other area of business. You have to make tradeoffs, and you need to understand what they are in order to decide the best course of action.
Note: If any of my students are reading this blog over the break, you should really follow the link and read the post