Well it's been a while...I *think* for the most part you should be OK, but then again you will likely have to enter the new 'commandline_format' settings for each emulator (you don't have this setting in v1.5 right?)
Best thing to do is download v1.61, and read the \docs\ini.txt file - have a look what's changed. I think the part I mentioned above will be the only major thing. John Crouse's website has examples for millions (nearly) of emulators if you need a guide - a link is at the 'help' page of my site.