The .bat file is:
So basically it launches the Bitcoin client and tells it where to find the data/wallet files.
The bitcoin.exe included doesn't match filesize for the most current bitcoin.exe from the official site, it's about 3mb smaller.
There's a libeay32.dll in with the bitcoin.exe, which is an OpenSSL library, if bitcoin.exe normally needs access to OpenSSL, then I'd assume this is just included as a dependency, if not then I'd be suspicious.
Just my quick look :-P