Unfortunately i don't think you can find such an app on windows mobile and if one arrives it will definitely not have the same functionality and user interface as the ones on iPhone but since you kept your iPhone you can continue updating your blog from your iPhone.
There are also tons of financial apps for Windows Mobile. But unlike on iPhone, you have to search for them on the internet yourself. The marketplace for WM just started and you shouldn't expect to find the same amount of apps as you do in AppStore.
I think both platforms have their advantages and disadvantages.
If you use iPhone you can download anything from AppStore real quick. But on the other hand you are limited to AppStore, unless you "hack" your iPhone.
On Windows Mobile you don't have such a nice AppStore (not yet, might come, who knows
), but you're also not limited to it. You can download and install anything you find from any source you like and from any developer you can find. That's also nice.
And with more and more "touchable" Smartphones based on WM, you'll also find more and more fingerfriendly apps.
You must see, that the iPhone is only one kind of device, which developers create apps for. WM is found on tons of different devices, each with different ways for data input. Some have touch-abilitys, some don't.
It's quite the same thing as the comparison of Macs and PCs.