I emailed Garmin about availability of their navigation software for the Storm. Got this reply -
Thank you for contacting Garmin International. There are absolutely plans to release our software on the Storm. Unfortunately, I don't have a date or even a timeframe on when that will become available. The Christmas season is of course very busy for us and it may be sometime next year. You should see a change on the Garmin website in the Buyer's Guide when it does become available.
so unfortunately, looks like we'll have to wait awhile, but hopefully it comes sooner, rather than later!