At my current project I deploy packages I'm developing in a subversion folder to the test environment by simply using the deploying capabilities of BIDS Helper in BIDS.

From test to production we have a script that simply copies the packages from one location (this can be the subversion folder or another) to the MSDB folder in the production SQL Server.

The script constains statements like this:

dtutil /FILE "\\someFolder\Release_x_a_b\SSIS\myPackage.dtsx" /DestServer /TargetServer /COPY SQL;"myFolder\myPackage" /Q

I think there are plenty of ways of deploying, but I'm only familiar with this one.

Regards.