With recent announcement of aws native provider, do we need to migrate from current aws provider to this new native provider? what exactly needs to be done? What are main benefits of doing this? https://www.pulumi.com/blog/announcing-aws-native/

we aren't recommending migrations for any existing workloads at this time. The native provider is still in preview and the resource support is dictated by availability on AWS Cloud Control API. In terms of the benefits, as the cloud control API matures, we expect it to have much wider and more universal coverage for AWS resources than the existing AWS provider

Is the next iteration of aws-x likely to be built on the native provider?

it's too soon to say for that answer I believe, it's very likely but I don't set our product roadmap