The 2-tier ( web + database) and 3-tier ( web + app + database) architecture are most prevalent today. There is however an emerging architecture that is gaining traction. This I am coining this the "Latency-tier architecture". In this architecture, a cache sits in between the customer facing front-end web components and multiple internal back-end web components.
OK then, let me coin Security-tier architecture. Let me go trademark it first to make a little money. I think caching, one of the proposed benefits of REST is a caching flag, is really an aspect of a service not an architecture. Portlet frameworks like JSR-168 have render/action phase where you normally cache in render phase. No need to claim a new architecture. Maybe just a pipe and filter architecture.