After becoming somewhat estranged open source, and spending some years developing web applications in ASP.Net, I\'m going to start doing quite a lot of PHP / MySQL development.
No, developing on wamp and running on lamp should be fine, but at least stage on lamp. I've gone both ways without many problems (ok, there used to be a bunch of problems deploying enterprise sites on WAMP (don't try to use the PHP ISAPI filter) but they are solvable now (fastcgi)). As long as you aren't adding any PECL modules that state they aren't supported on Windows, you shouldn't have any problems. Also (since you are stating you are using WAMP I assume you are using MySql), mssql and PHP have a bunch of issues (the ancient driver it requires seriously limits the length of your query).