Back in the days, when I was hacking on Gazpacho I found the lack of types on variables and function/method parameters really annoying in Python. This can become quite a pain when you are reading other's code and that is exactly what I was doing most of the time. The fact that Johan and Kalle wrote very nice and readable code, helped a lot though.
- No runtime dependency/overhead
This might seem like a small point to many developers but as an embedded-systems developer, this is a big plus for me and I am sure to many (if not most) of the embedded-systems developers out there.
- Easy integration with C/GObject
A big plus for all the GObject/C developers out there. Besides, there are situations when writing code in any language other than C or C++ is not possible/viable and such easy integration would make life very easy. Recently a colleague of mine had to bind a gobject-based library for Python and it turned out to be a lot more pain than I imagined. This impression is based on the fact that so many of GNOME developers have taken python so serious and so many of the GNOME apps are being (re-)written in Python.
This point is very important when it comes to writing frameworks and libraries since if you write them in a language that doesn't qualify as a LCD, you are pushing your choice of language on the application developers you aim to attract. Since Vala translates to a language that does qualify as LCD, it in turn also qualifies as one.
An important bit here is that this integration is bi-directional, i-e one can use the classes written in Vala very easily from C. In fact this is much easier than doing it the other way around as you don't have to write any bindings.
UPDATE:I am sorry if my ideas hurt someones's feelings attached to some particular language. If i have hurt your feelings, there is no need for insults, I didn't force you to read my blog. Just writing this after removing an insulting comment from an 'Anonymous' dude.