So today Microsoft has released another build to techbeta testers. The build is 5728-16387 and the details are given below :
vista_5728.16387.060917-1430_x86fre_client-LRMCFRE_EN_DVD.iso, 2,622.25 MB
vista_5728.16387.060917-1430_x64fre_client-LRMCxFRE_EN_DVD.iso, 3,628.64 MB
The build is basically from RTM branch so you can expect a lot bug fixes and improvement but dont expect anything like new interface or goodies because those will be coming only in the RTM build.