Have noticed some models being sold with lifetime updates, but not all, so don't hold your breath.
I have an S40 that looks like being used as a sinker whilst fishing as I can get a new GPS for less than map updates unfortuneatly.
You can upgrade your old units to one of the newest range of MY-Series that includes lifetime free maps. You can do this at our online store, just select the trade-in option from the menu.
I hope that helps, but let me know if you have any other questions.