As promised, here is the update.
For Mads and whomever is interested in building the Second Life client on Solaris (x64), this is what I did.
Please do remember, these are just to get the client build on Solaris. I havent completely run the client yet (nothing beyond the login screen). So, buyer beware.
Basically, I followed the Linux instructions in Second Life Twiki page.
Downloaded and built all the libraries mentioned and copied the libraries and headers in the directory under, 'i686-sunos5', instead of 'i686-linux'
Modified SConstruct (for scons building).
- Look for 'linux' and introduce the code for 'sunos5' (replace -DLL_LINUX with -DLL_SOLARIS)
- Remove the 'db-4.2' entry under libs line.
- Replace 'yacc' with 'bison -y'; 'lex' with 'flex'; 'g++-3.4' with 'g++' (under /usr/sfw/bin); 'strip' with 'gstrip'
Whichever subdirectory contains 'files.linux.lst', make a copy of it called 'files.sunos5.lst'.
Then comes the code changes. Basically, search for files containing 'LL_LINUX' and add "|| LL_SOLARIS" or "&& ! LL_SOLARIS" as appropriate.
In llcommon/llpreprocessor.h:38, I added "|| (defined(LL_SOLARIS) && !defined(__sparc))" to the line to set the ENDIAN correctly.
In llcommon/llsys.cpp, I added code to use the output of 'psrinfo -v', instead of reading from '/proc/cpuinfo' for SOLARIS. Similarly, used 'getpagesize() * sysconf(_SC_PHYS_PAGES)' to get the "Physical kb". I know there are better ways, but just wanted to get the build completed.
In llmath/llmath.h, I was running into some problems regarding 'isfinite'. I replaced with this.
#define llfinite(val) (val <= std::numeric_limits<double>::max())
The other significant work is in 'llvfs/llvfs.cpp' and 'newview/viewer.cpp'. Replaced the code for 'flock' with the appropriate 'fcntl' code.
In files 'newview/lldrawpoolsky.h' and 'newview/llvosky.cpp', replace the variable 'sun' with 'Sun'. 'sun' in a SunOS is defined already, of course.
In 'newview/viewer.cpp', rewrote the 'do_basic_glibc_backtrace()' to use 'printstacktrace()' instead.
Well, you can follow the above instructions, or send me a mail, I will send the diff output. 
For runtime, you will have to set your LD_LIBRARY_PATH as mentioned in the Twiki page.
Thats all I have for now. Will update later, if any.
Regards
Siva
PS: It is indeed a pity that I cant login to a server named after me
(userserver.siva.lindenlab.com)

Any one knows a way to achieve this?