Why? Too manu bugs? The 1.01 version is still available at various FTP-sites, but not at MyDlink support section.
According to my experiences the 1.01 version is at least as good as the original 1.00, but I must admit that I'm not using all the special motion detection and event features, etc.
I was too optimistic about the audio problem. Unfortunately the clicking has not gone away with the new FW release, but as said earlier the automatic exposure control is now working better and also I have now the live video available through MyDlink web interface (Win7/IE9) without using the Advanced Settings tab.
So I haven't personally noticed any reason why the 1.00 would be better than 1.01...