>If you design things as n-tier and componentize now and 2 years down the rode you need to change things, it makes it a helluva lot easier to do it (IMO).

Hypothetically, 4 years ago I wrote a web app using J++ and Jet data access, very n-Tier. Last year, I rewrote it to be n-Tier again using VB6 and COM with WIndows DNA and SQL Server 2000. In three years, in order to be felxible in the future, it needs to be upgrdaded to a .NET app. In three more years, the .NET app will be flexible, but it won't be flexible to the group 3 years after that since .NET will be 6 years old and it will be a whole new ball game.

>You can incorporate the new and incompatible technologies (somewhat easily) by writing an interface between one existing tier and the new one.

So who's going to support all 2 old tiers plus the 1 new teirs and the 2 wrapper tiers in between since the new 1 woudln't go right in between the existing two? Why not re-write the app to fit the new businnes world and the new hardware world? Its a nice theory, but I'm not buying it.