In reference to using deprecated mark-up...
Is it going to hurt anything, no. Is it going to cease to function anytime soon, probably not. However, CSS was introduced to cure the mixing of structural mark-up from presentational formatting. Using CSS-based solutions and XHTML or XML compliant mark-up, 1, prepares your designs for the future, and 2, encourages browser creators to further implement the latest CSS standards (Namely Internet Explorer, the others don't need encouragement at this point). Such trival CSS 1 properties like vertical-align are also widely supported by the ghosts of browsers past. The only time you really need to look out for using deprecated mark-up is when you use a DOCTYPE that invokes standards mode. A browser in standards mode isn't supposed to allow deprecated mark-up.
: )
Rich
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The Spicy Peanut Project
http://www.spicypeanut.net
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