Developing a Standards-Compliant Web App?

dogas queries: "I work for quite a large company that is creating quite a large web-based enterprise-level application. We've been in development for a long while, and currently our app is only native to IE 5.5. At this point it would take a *lot* of effort to bring our app up to to be Standards-compliant. Now management wants our app to be more flexible, such that if the customer wants to customize the look-and-feel, it won't be a major undertaking that will kill the structure. Naturally, we're switching to a CSS-based layout, ripping out the IE proprietary Javascript in favor of ECMAScript, and bringing the whole app to XHTML 1.0 Transitional compliance while we're at it. Since we started coding the front end at about the time of the browser wars, we didn't have the luxury of planning to use the W3 standards (especially since they were not complete, and browsers weren't honoring them anyways). I'm wondering what type of priority creating a standards-compliant web app is in other companies, and if that priority is being raised given the benefits of creating pages that separate structure from style from behavior."