yeah right....you mean how well they supported WM6.5 after 7 came out?
You have to understand something, the leap from Windows 6.5 to Windows 7 was significant enough to warrant a change in the business model for Microsoft and supporting the ailing Windows Mobile line outside of enterprise contracts wasn't beneficial to MS. Microsoft wanted, and received, hardware support and buy in from the likes of Samsung, HTC and Nokia. You couldn't ask them to continue supporting their WM 6.x devices if what you were pushing going forward was drastically different.
The big change with 7.x to 8.x is the kernel. This enables a lot of hardware centric applications to now be applied whereas in the past this couldn't be done. NFC, 1080p recording, dual core processors, etc., will bring Windows Phone into the modern superphone era. The OS is going to be leveraged as a more elegant solution to mobile computing than iOS and Android. What can't be done on a 7.x device once it gets 7.8 will be evident. Will it kill the brand? No, but you will have some vocal consumers on forums complaining that they have a terrible phone. No, you liked your phone in April when you thought it would get Apollo but now that 7.8 is the stop gap you are mad. The Lumia still operates the same way, just not how you wanted it to with Windows 8.
I'll admit I want a Lumia 920 after seeing what it can do. My Lumia 900 is still a fine phone and arguably one of the best - if not the best - phone I've owned. If the 920 took what I don't like about the 900 and corrected those problems then that takes things to eleven. If the 7.8 update takes some of the issues with the Lumia 900 that are software specific and improves upon them or puts a fresh spin on a phone I will have to stick with for a while that's fine. When the phone gets its update it won't be a situation of putting lipstick on a pig - far from it. This phone was never bad to begin with.
I won't go as far as saying the Lumia 900 is fine as it is and shouldn't get the 7.8 update. That's very opinionated and suggests nothing is wrong with it which isn't true at all. I expect a new start screen - from there I have no idea what they could actually address, correct or even improve upon with 7.8 so I won't go into it thinking that a bump up in version will mean it can do my taxes come April 2013.