I was present for the perl4 to perl5 shift. It was pretty fierce. Lots changed and there was a great wailing and nashing of teeth. In the end, most of the old scripts continued to work ( albeit with strange new warnings and errors ) and there were many docs written to support you translating your scripts from perl4 to perl5.

The downside of this is I know people who are still saying they need to learn the new perl5 features and still write their code as close to perl4 as they can.

Wait to see what happens. Experience says you will not have to do it overnight - very few places will immediately upgrade. Other experience says the perl6 developers will try to keep a good balance between breaking needlessly and breaking for the sake of real advances. Most things will be depricated in perl 6.0, and will outright break on perl6.1.

mikfire