It is a good question i think.
Though i don't really need bleeding edge software technology, progress dose have influence over the decisions i make whether to use SME or some other server software.
We have to keep in mind that the right path is the middle one and not only the conservative or the extremely new ones.
If SME 8 doesn't even reach the RC stage soon, i for example will have to replace it with some other updates server software BECAUSE SME7 can't provide the platform for a lot (and growing) updated software versions of "addins" - contribs if you may, like Wordpress (next gen will require sql5), Subversion (Centos 4 only support up till 1.4.6 - now there is 1.6.x), and a lot more ...
I understand the problem of having little funds and relaying on contributed time of developers to progress but open source projects have almost all the same conditions to evolve right ?
Don't get me wrong, i think SME server is the best way to provide a stable environment for small offices and I'll install it back as soon as 8 will take the next step towards final and become RC but for now, i do not have a choice but re[lacing 7 with some modern servers like Zentyal or ClearOS that basically provide the same basic functionality SME dose but with higher compatibility to NEW versions of added software !