Automated Text Formatting between LaTeX and Textsoap?

I am wondering if there is a tool to automatically format a page of word processing (or plain) text that is somewhere between LaTeX and Textsoap. Textsoap (and its competitors) works well for removing cruft from a file, but doesn't do a good job of fixing a file's formatting.

Let's say I have a file where paragraphs are separated by a blank line. At least, most of them are. But some of them are not. So it looks like this:

Here is a paragraph full of text.

Here is a paragraph full of text.
Here is another paragraph, but no line break.


Here is a paragraph with the line break. Is than an extra line?

Here's a paragraph with odd formatting. There's a line break 


and an extra line in the middle of a sentence. 

I can use LaTeX to typeset this mess consistently (among other things, LaTeX will ignore blank lines). If there were stray >> characters (there's not), Textsoap will gleefully remove them.

But I don't know how I can--except manually, fix the text so that full paragraphs are separated in all cases by blank lines, and paragraphs do not split across blank lines.