What about the situation? That would produce two spaces, that's how it renders in Firefox and in IE. Though if you had:
Code:
<p>one <span> two</span>
which is 2 spaces between the <span> and two, it would reduce to 1 space.
HTML creates a tree of its elements (Which I'm sure you're aware of).
Code:
<p>
"one"
<span>
" two"
</span>
Since almost all browsers reduce extra whitespace down to 1 within any given tag, except those that are designated as white-space:pre or within <pre> tags, then it would be safe for you to eliminate all extra whitespace that exists within individual tags. Though, if that whitespace happens to already be 1 space in size then there's no reason to eliminate it.
That's how the browsers do it. If you wish to faithfully reproduce the same look as in the browsers, then do what they do. Instances where you want a single space between one and two above are going to drive you nuts. And I'd say, unless there is style information tied to a tag that you ignore the tag.
Since, in this case, unless there is a specific style attributed to the <span> tag, I'd simply ignore it since it's not doing anything.