I don't think it is coming to an end for the time being, as they have just announced or have come out with 13, but WP doesn't do a great deal to make it easier for its users to play well with others, for sure.
Still, there are a few things you and those who receive your material can do to work "cross platform", if that can be said of a word processing program.
First and probably easiest, you can save your wp documents as word files by clicking >file >save as, then chosing MSWord or Rich Text File under File type. The document you send should be whatever.rtf or whatever.doc. The recipient target will be able to open it nicely. The nice thing about rich text is that it is generally not susceptible to virus infections.
Second, from the standpoint of the word user, Msoft has a free conversion utility available. I believe it is actually on the instsallation disk, but if not, it can be downloaded from the MS site (as can conversion uitlities for just about everything but Clarisworks..Bill is still playing hardball with Jobs, apparently).
The windows user can open your documents then by opening them directly from Word (>file >open etc) or can right click on the icon and choose "open with" >Microsoft Word from the right click menu. Once they have done this, wpd files should continue to open in word.
Downside here is that some fancier formating may be a little boondoggled, but if all you are sending is text (as an author/writer) the fancy lines and text boxes probably matter less.
Note that Word Perfect has fewer conversion options than Word. For this reason I have both of them on my computer. They play together very well.