Here's the results from last week's survey, asking Second Life users on this blog what they would need in order to get a Premium account. With 200 responses, this is a relatively large (if informal) data sample of hardcore SLers, so it's notable that nearly half already have a Premium account. If all of SL's roughly 600K active users converted to monthly premium, Second Life could exist into perpetuity, despite constant loss of private land sims and tier. So it's notable that a strong plurality wants a larger tier allotment to make that upgrade.
Also, there's copious amounts of virtual land on the main continents of Second Life. According to analyst Tyche Shepherd, over 20% of the mainland represents abandoned land. So Linden Lab could easily expand the tier offering for Premium subscribers.
Expanding tier would probably also encourage existing Premium holders not to downgrade. As reader "Snowhawk" puts it: