It's true that most of us like changing from time to time (we wouldn't be at a Windows Customization site otherwise, would we?). True, everybody likes to have the latest and greatest, but... just changing the name of something does NOT make it the latest and greatest. What matters is content. If the content is the same, you can come up with the coolest name in the world and whatever you are selling is still the same, old, stale product. Be it a skin, a program, a car, or whatever.
And then there is something called 'branding'. In branding we want people to associate a word with a product or a range of products. For example, you can call it 3.1, 98, ME, 2000, XP, Vista and whatever, but it is still WINDOWS something . It's not good to keep changing the name of your product, sacrificing it in the altar of 'freshness': you will lose that recognition that took you so long to gain.
Plus, think about what you said: 'don't ask me to use the same WB skin for 1 year, I will commit suicide'. True, you're not using the same skin, but you are using the same PRODUCT - and some people here have been doing so for over 5 years.
The advantages of a 'subscription based' model for UPDATES have been amply discussed above, and they are valid for any software company, be it a startup business or not. Again, don't confuse this with 'renting' software - that is something completely different that would, in my opinion, never work in the real world.