Boss, you have misunderstand on GWT and Gears

It is good for "classic Web development" to "Web 2.0 development". It is not for moving from fat client/server  application to web based application.

It cannot not do persistent, share, or collaboration without a server. You always need (at least) one server unless a classic client/server fat application.

- "database" in Gears is a rich replacement of cookie, by using of sqlite
- GWT is "Java like syntax", it is not Java. You cannot migrate your swing application to GWT. You can only share these soruce code in very very extreem cases.

From my point of view, RIA / AJAX are hot because they can  provide Rich user interface and can save some development time on "supporting function".

AJAX Web application can help you that do a 3-tear application, rather a 4-tear application.

e.g.
old 4-tear :
Browser HTML <-> web app (control of GUI here)<-> web services <-> databases
AJAX 3-tear :
Browser AJAX/RIA <-> web services <-> databases

Programmers can spend less time on fighting with broad width, HTTP 1.1 specification, browser compatibility.