A RadioShack tweet from yesterday has tipped the launch date for the upcoming Sidekick 4G from T-Mobile and Samsung.  Expected to land in the coming weeks, we can now look forward to Wednesday, April 20th.  Given that the tweet hasn’t been pulled down or refuted by T-Mobile, we’re pretty sure this is final stuff.  Be sure to check out a few videos of the Sidekick 4G in action if you’re not up to speed yet.  Are you grabbing one of these Android-based beauties or have you moved on from the Sidekick form factor?