In order to keep up with the "trend" of modern design techniques you should really learn CSS and tableless (or less-table ) design practices. The key benefits I can think are as follows:
1) Using CSS makes your site more accessible to those with disablities and textbased web browsers (Lynx).
2) CSS makes your code easier to read and understand by search engine bots. (and yourself sometimes)
3) It's good practice to keep your Presentation/Layout layer seperate from your Data/Content layer. (updating is in-fact easier).
Think of it this way: You wouldn't use Excel to design a webpage so why would you use tables. Move on to CSS and don't look back.
Webpages with CSS are nothing without HTML ^_-
Perhaps my fault, but the thread thinking has deviated into assuming tabled designs make no use of CSS. This is far from the truth.
CSS by itself does not make sites more accessable, or search engines more effiicient. Using CSS may make sites more accessable, or it may make them less accessable.
Consider, a user with moderate long-sightedness; who prefers to view pages without any stylesheets atall. Not by overriding certain stylesheet rules, but by completely overruling stylesheets.
Anything now that uses CSS to re-order page content in a "tabular fashion" fails immediately and to the user, un- interpretably. Any organisiton of data is now as the document would read in markup, with markup-standard headings, fonts, and positions where elements are used. Tables noteably, still hold data in the same relative place.
Consider now, that instead of overulling stylesheets, the user reads a site with tables with their screenreader. The screenreader is optimized to deal with tables intelligently, as a table can be logically split into columns and rows, and read in a user specified order, perhaps with an aural repeat of headings on every other row for clarification. Even visually, a linearized table can still be interpretted using a reading convention rather than a series of reading assumptions.
A site using CSS to rearange content will hit a potential problem, depending on the screenreader used. Unfortumately, screenreaders are not a very well developed end of the software industry; ones I have tried only read in markup-order, and do not respect relative positioning of text blocks with respect to reading order. Of course, this favours well organised content. But it doesn't take CSS into account whatsoever (aural CSS rules do apply, but visual rules for the most part do not apply, and/or are not well standardized).
Using CSS makes your code as easy to understand as your code without CSS is easy to understand. If your code is not easy to understand, CSS will make it no easier. If your code is easy to understand, a lack of CSS will not make it more difficult.
It is good practise to keep the data and presentation layer separate, CSS and HTML are both presentation layers. Lynx sees HTML as the only presentation layer. Lynx doesn't care what your CSS stylesheet says. DIV hacks make Lynx-viewed pages vertically enourmous, tables are interprettatable in Lynx, because they are displayed as indented lists.
Finally, you shouldn't do anything to keep up with trends, by definition, a trend is in passing.
And even more finally, you can't move "on" to CSS. You can move "in" to CSS, but if you jump onto CSS and think you can leave HTML behind, you'll be more than a little marooned.
Personally, if I could design pages in Excel, I would. Excel has a predisposition for automation, and a concept of value transference across multiple dimensions through an infinate choice of functional gateways. Excel + CSS would kick a$.