I'm thinking about replicating a production MySQL database to my development machine so I have always got current data.

The development database is externally located. My development machine is behind an hard to rely on web connection. It's feasible that the expansion machine might be disconnected from the web for longer amounts of time (hrs).

Would there be any adverse impact on the development database using this method?

(I do not strictly need live data - but it might be nice, and good excuse to dabble with replication. When the consensus is this fact is an awful idea, I'll setup a regular job to import the prior night's backup into my development database)

Getting real information is always beneficial in development. Be sure that you blank every user's current email address which means you don't junk e-mail all of them with development emails.

As lengthy as you are not affecting the expansion atmosphere for that relaxation of the team (there's no harm testing your application with production data). However, this special atmosphere ought to be stored outside of your dev/stage conditions (refer to it as, special-stage, or almost-production).

And what if you want to change database schema or perform some experiments with data/triggers/SP/constraits? once you have modified the information on slave - it will likely be in asynchronous condition ever, until next dump importng + syncing.
so why wouldn't you then simply do dump imports sometimes?

I believe inside your conditions - yes, it's bad idea. To build up, one have no need for any actual data, even daily up-to-date one. As well as your internet connect conditions is poor for enjoying with replication.

Have you got any sensitive data inside your production server (emails? telephone numbers? passwords?). I'm not sure if the is applicable for your atmosphere, but occasionally security rules are less stringent on dev machines than you are on production servers ("what's that? all of the designers say they require root use of install CPAN modules? -- sure, not a problem, it is simply a dev box").

If there's sensitive data involved, consider whether you are growing your exposure by copying it to a different machine.

(and does the replication make use of a secure (SSH) connection?)