First stab at this package:

1) On BuildRequires:

You only need to require xerces-c-devel (this package requires the non-devel main package as per the guidelines for -devel sub-packages). Minor issue, no showstopper.

2) rpmlint:

$ rpmlint /home/jmeeuwen/rpmbuild/RPMS/x86_64/blahtexml-0.6-1.fc10.x86_64.rpm
blahtexml.x86_64: E: description-line-too-long Blahtex is a program written in C++, which converts an equation given in a syntax close to TeX into MathML. It is designed by David Harvey and is aimed at supporting equations in MediaWiki.
blahtexml.x86_64: E: description-line-too-long Blahtexml is a simple extension of blahtex. In addition to the functionality of blahtex, blahtexml has XML processing in mind and is able to process a whole XML document into another XML document. Instead of converting only one formula at a time, blahtexml can convert all the formulas of the given XML file into MathML.
1 packages and 0 specfiles checked; 2 errors, 0 warnings.

Easily fixed, of course ;-)

3) Source0:

Source0 should be the URL to the upstream tarball.

Thanks. I have modified the files.

Whenever you do, please;

- bump the release number in the .spec (and add/modify changelog entry/entries)
- rebuild the source rpm with the new spec
- upload
- link the new spec file
- link the new srpm file

As you wish :-)
specfile: http://bender.newnewyork.nl/review/blahtexml.spec
source-rpm: http://bender.newnewyork.nl/review/blahtexml-0.6-2.fc11.src.rpm

Informal review:

Looks good to me, the only quibble I would have is the make command does not use flags to enable parallel make and there are enough source parts to warrant using it.

http://fedoraproject.org/wiki/Packaging/Guidelines#Parallel_make

i.e. change 
make blahtexml-linux
to 
make %{?_smp_mflags} blahtexml-linux

which is faster on my system

Thanks!
Updated:
specfile: http://bender.newnewyork.nl/review/blahtexml.spec
source-rpm: http://bender.newnewyork.nl/review/blahtexml-0.6-3.fc11.src.rpm

* When using "install" (or "cp") to install unmodified files yourself, prefer option "-p" to preserve timestamps. This is considered helpful by users, who want to recognise the age of files (e.g. ancient documentation). Otherwise it shouldn't be overrated. ;)


* Our global compiler flags are not used:
https://fedoraproject.org/wiki/Packaging:Guidelines#Compiler_flags


* Please drop "Requires: xerces-c" in favour of rpmbuild's automatic dependency on the "libxerces-c.so.28" SONAME.

Thanks, all done:
specfile: http://bender.newnewyork.nl/review/blahtexml.spec
source-rpm: http://bender.newnewyork.nl/review/blahtexml-0.6-4.fc11.src.rpm

OK... the changes look good. I'll approve the package. 

I see that you need a sponsor. I've only just been sponsored myself but if you carry out a couple of package reviews:
http://fedoraproject.org/wiki/Packaging/ReviewGuidelines
(or submit other packages for review)
and link to them here then I'll sponsor you.

(Michael who sponsored me is still cc'd to this bug so I suspect/hope he'll keep an eye out that I don't make any huge blunders)

You would need to become a sponsor first:
https://fedoraproject.org/wiki/PackageMaintainers/SponsorProcess
I'll look at "gvrpcd" and sponsor Jasper...

Thanks! :)
I applied to the packager group in FAS (account name: jasper).

New Package CVS Request
=======================
Package Name: blahtexml
Short Description: Converts TeX equations to MathML
Owners: jasper
Branches: EL-5 F-9 F-10
InitialCC:

cvs done.

blahtexml-0.6-4.fc9 has been submitted as an update for Fedora 9.
http://admin.fedoraproject.org/updates/blahtexml-0.6-4.fc9

blahtexml-0.6-4.fc10 has been submitted as an update for Fedora 10.
http://admin.fedoraproject.org/updates/blahtexml-0.6-4.fc10

blahtexml-0.6-4.fc9 has been pushed to the Fedora 9 stable repository.  If problems still persist, please make note of it in this bug report.

blahtexml-0.6-4.fc10 has been pushed to the Fedora 10 stable repository.  If problems still persist, please make note of it in this bug report.