Getting a longer runtime for my cordless blower

There is an upcoming product announcement from one of our manufacturers which Matt has mentioned in his article "It's time to put your favorite tools on Lituium (ion)". No specifics yet, but you can probably guess who and what the announcement will be without all the details or specifics. At first, this seemed sort of like just a geeky thing to do to me. Changing battery technologies is cool and all, but for an IT guy how useful would that really be? Well, I'm having trouble deciding.

High Drain Applications
Obviously, longer runtime is a big deal for high current applications. If you only use a cordless flashlight there's not a real reason to switch, unless you're in Alaska and have those 24 hour nights and no charger. Ok, so you'll have to consider it twice there too with the charging problems with cold weather. But when you've got a geeky tool like the Makita UB181DZ which boasts a whopping 9 minute runtime, Lithium Ion may become a HUGE deal. Even if it only doubles the runtime, I could probably get all the grass clippings off of my driveway without swapping batteries.

Fewer Batteries
Right now, I have 4 batteries for my tools. I typically have to use 2 fully charged batteries for blowing off the driveway, sidewalk and patio. I have one always on my flashlight and one is usually in my drill. Being able to do the same amount of work with fewer batteries is cool on the geek meter, but is it truly practical?

Tough Choice
I'll probably get one for the blower and eventually have fewer batteries when some of my current ones start to die. By then, I should know what makes sense - longer runtime or more batteries. Once I have it figured out, I'll let you know what I decided.

The delimma is this: sometimes it's handy to have more batteries, but other times I'd love the longer runtime. I guess it comes down to how many tools do I want ready to go... and how much of an inconvenience it is to swap the batteries back and forth. That means it is subjective and it comes down to personal preference, so there is no right answer.