Well, having read through a lot of the discussion here, I must say the complexities of this issue fascinate me - most aspects of language do. And although I didn't even know of the existence of the two writing systems, I am now going to wade into the discussion from a technical and just generally interested point of view.
One of the key issues seems to be to what degree the two writing systems differ: are they just different representations of the same language, of different dialects, or do they represent fundamentally different languages?
For instance, 簡睦旼 mugua_q0_0p@yahoo.com.tw wrote:
Yes, Traditional Chinese and Simplified Chinese are originated from the same language. But now it had grown into two different language. The problem of translating Simplified Chinese to Traditional Chinese is not only about characters (While translating from Simplified character to Traditional character is already a headache).Many of the phrases and idioms are different.
Others have suggested that "most" words and phrases are the same, just written differently, with exceptions in specific areas. Henry H. Tan-Tenn gives a specific example:
... Will PRC users accept that a computer is known as an "electronic brain" in Taiwanese Mandarin, and not as a "calculator"? Will a Taiwanese Mandarin (or Japanese) user accept that what looks like the term for "calculator" often refers to a "computer" in PRC Mandarin? Clearly such differences can not always be avoided, and one or another or both have to be used without affecting intelligibility for one of the user groups. The evolution toward mutual textual intelligibility (through learning) and mutual acceptability (through tolerance and/or compromise) might *eventually* contribute to some kind of International Mandarin. Probably there are already transnational business incentives to do so.
Of course, this may not be a representative example of the general kind of difference, but it suggests two things to me:
1) The differences (beyond character mapping) are not particularly major. The comparison that springs to mind is US vs UK English: most of the differences amount to spelling conventions, such as color/colour etc, but there are some terms that are quite different, like sidewalk/pavement. A good example is "jelly": in the UK, "jelly" means a kind of pudding that in the US is generally called "Jell-O"; in the US, "jelly" means a fruit spread that in the UK is generally called "jam". Things like this do cause occasional confusion, and even friction, in international English projects, but en.wikipedia: doesn't seem to suffer a great deal from trying to appeal to both audiences. Now, I'm sure this comparison isn't perfect, but from what people have said so far, the Chinese issue is far more similar to en-gb vs en-us than it is to, say, en vs jp (an example somebody gave where it would be very hard to meaningfully merge the projects).
2) There is a tendency to equate the different dialects of Chinese with the different writing systems, when the two issues may in fact be more or less orthogonal. That is, the Taiwanese use of "electronic brain" for "computer" is a *dialect* issue, which probably exists in speech as well as writing, and there are probably far more dialects with such differences than there are writing systems. Such differences occur in all languages that have diverse populations of speakers: in English, we have not only US and UK variants, but Australian, Irish, Scottish, 'Black English' ('Ebonics'), etc etc. If the differences between dialects/variants of Chinese are genuinely more complex than these, then this needs to be discussed *independent* of the discussion of writing systems.
I understand that the issues necessarily overlap, but if there are multiple dialects/variants that [can] use the same writing system, and multiple writing systems that [can] be used fo the same dialect/variant then splitting the project based on one variable won't solve the problems of the other - you will either have a single-charset project where multiple dialects still have to coexist, or a single-dialect project where multiple charsets still have to coexist.
Well, that's added a lot of words and probably not many ideas to the debate, but I thought I'd throw my thoughts into the mix...