Over at killerphp.com, Stefan Mischook is contemplating whether Ruby (on Rails or otherwise) will kill PHP. His article, Will Ruby kill PHP? outlines why he believes Ruby will not kill PHP.
Will Ruby kill PHP? The short answer is: no.
If you want the long answer, you’ll need to head over to his blog and check it out.
Oh hey, and while you are there check out his tutorials. They are probably under the feet of most the people reading this post. However, they are great for recommending to friends who want to know more about PHP. They are specifically designed for web designers. My wife (the lovely and talented Kathy) is working through them and was real proud today when she showed me her Hello World! As the target audience for these tutorials, she highly endorses them.

Comments
I reuse classes all the time for things that are in most applications I write--file controllers, user stuff, formatters, etc. Getting a project to the "does something" stage is about the same for simple things and faster for complex things than when I wrote procedurally. It's because of this ability to reuse, and it has the benefit of being more maintainable (merging changes in reused classes), easier to debug, and more scaleable.
<blockquote>"With OOP, there is a cost of added complexity and overhead - you simply have to write more code to do things when you do it via OOP."</blockquote>
Not quite; you have to write more code <b>the first time</b>. After that you reuse/adapt. My own preference is for clean, readable code like <code>$object->save()</code> and <code>function upload(File $file)</code> and iterable collections.
<blockquote>"PHP PROVES THAT NON OO LANGUAGES STILL HAVE THEIR PLACE"</blockquote>
The question is not whether or not Ruby will supplant PHP in the "trivial e-mail form" area of the market. It's whether it is a viable contender to PHP for the real-world OO application market. Currently, the answer is no--but remember, PHP didn't take off until version 3. Honestly, I think the biggest problem for Ruby is expectations. People see what `scaffold` can do and think the entire language will be that easy, and then when they discover that they actually have to learn Ruby (the horror! ;-)) their interest goes down dramatically.
I think there's a place for both, and that Ruby's popularity will gradually increase with time. What's <b>really</b> going to set PHP apart, though, is Unicode support in version 6.