The short answer is 'No' as LaTeX is the incumbent and quite good at its job. It's also free, so there is relatively little commercial incentive to attempt to replace it. In fact, TeX is sufficiently good at technical publishing that the commercial market for technical publishing tools is rather squeezed between TeX at the 'geek' end and word at the 'great unwashed' end.
The longer answer is 'There are alternatives'. LaTeX and other packages suffer heavily from leaky abstraction issues and often require technical intervention to get what you want out of it. This puts you in the business of understanding how it works behind the scenes, which is actually fairly technical. Thus, you can only really use it for non-casual applications if you have access to someone with that level of technical skill. Writing a report or book is fine. Building a single-source technical documentation workflow with LaTeX is quite a different proposition - you will need access to someone with a technical skill base.
Alternatives to LaTeX
Commercial technical publication
tools. There is really only one
left standing: Framemaker.
This is a mature product but
somewhat stagnant. However, it does
have an open document and segment
interchange format called MIF,
a comprehensive API and extensive
support for structured
documentation. It's quite widely
used in aerospace circles (for
example) where reference documents
for aircraft run to tens of
thousands of pages. Additionally,
there are
several also-rans in this space:
Ventura Publisher,
Arbortext (which is based on a
TeX derived back-end IIRC), and
Interleaf, which is now known
as Quicksilver.
Adobe claim to be implementing
technical publishing functionality in
InDesign but I have not really
evaluated its capabilities for this.
Lout A markup language with a
completely different underlying
architecture to TeX. I've never
worked with Lout but I believe that
it is somewhat easier to work on
behind the scenes than TeX.
Troff/Groff. Originally designed for technical documentation within AT&T during the 1970s (actually a spinoff of the UNIX R&D work), it's still quite widely used for this today. For quite a long time most if not all O'Reilly books were typeset using it.
DocBook. This is an XML tag
based format for structure
documentation, and tends to work by
rendering through foreign engines.
I've never used DocBook, so I can't
really comment on its usage in
practice.
Wordperfect. This is a
venerable word processing system
that is considerably better at
documentation-in-the-large than MS-Word.
Although viewed as something of an
also-ran it retains several niche
markets such as law offices and is
reasonably good (at least significantly
better than Word) for large, complex
and heavily cross-referenced documents.
Microsoft Word. Not
recommended for serious technical
publication tasks due to its
instability on complex documents.
However, as often as not it is the
only choice due to political
constraints. Indexing is especially
painful.
EDIT: See this Stackoverflow post for a more in-depth rundown on Framemaker and other technical documentation tools. It's an answer to a question about technical documentation tools for someone who specifically didn't want to use a markup language based system.
