If you're feeling good about the market, you're not alone. Take my hand as we go over some of this week's more uplifting headlines.

1. A killer app
It's official. Apple (Nasdaq: AAPL) will be rolling out the Mac App Store on Jan. 6, hoping to catch lightning in a bottle again.

Apple's success with the original App Store for its iPhones, iPod touch media players, and iPads running iOS has been huge. Will the same folks who flock to free or nearly free apps on their touchscreen gizmos still be interested when more powerful Macs and MacBooks with actual keyboards come into play?

There's plenty at stake here, and Apple is making it clear to developers that the opportunity to clear 70% of sales revenue is an opportunity that they don't want to blow, either. In other words, there will probably be compelling programs showing up in a few weeks.

Keep an eye on this, because it could revolutionize the way we use computers. Browsers and costly conventional software will be less necessary if self-contained programs help us complete our computing tasks. At the very least, the Mac App Store should draw attention to Mac computers for iPhone, iPod touch, and iPad owners who haven't made the full Mac migration. A well-stocked Mac App Store will make the premium that Apple commands for its systems easier to stomach.

Your turn, Microsoft (Nasdaq: MSFT). Let's hope that you're not slow on the uptake this time, too.

2. Pop goes the world
SodaStream (Nasdaq: SODA) scored a one-two promotional push for the health and eco-friendly merits of its portable soda makers this week.

On Monday, Dr. Oz featured the $100 system that carbonates water on his show as one of this season's five healthy holiday gifts. Why not? Even SodaStream's non-diet pop contains just a third of the calories, carbs, and sugar of store-bought soft drinks.

The next day, Soda Stream snagged a 2010 Green GOOD DESIGN award for the product's eco-friendly appeal. Instead of cans and bottles that may or may not be recycled, SodaStream employs reusable 1-liter containers that are simply rinsed out before being placed back into fizzy action.

SodaStream's IPO was originally billed as the soda world's Green Mountain Coffee Roasters (Nasdaq: GMCR), but it's really more of the anti-Keurig.

The Keurig single-cup coffee brewers provide convenient premium java that is substantially cheaper than trekking out to nearest barista. SodaStream's flavored soda concoctions -- at the equivalent of $2 for a 2-liter bottle -- are slightly more expensive than store-brand soda.

However, while Green Mountain gets blasted for the eco-endangering nature of its tossed K-Cup refills, SodaStream is green -- even if its sodas cost you more greenbacks.

3. Playing to win the game
Take-Two Interactive (Nasdaq: TTWO) had a hard act to follow heading into last night's fiscal fourth-quarter report. It came through with an unexpected profit three months ago, and the pros weren't going to be fooled again. They set the bar high, expecting the video game publisher to more than triple its non-GAAP earnings.

What did the company behind the Grand Theft Auto franchise do for an encore? It posted an adjusted profit of $0.67 a share last night, more than double the $0.31 a share that Wall Street was targeting. Revenue also climbed 32%, though analysts were braced for a top-line decline.

Now you've done it, Take-Two. Folks will expect free ponies and a shower of pearls next quarter.

4. On the right Path
There's another mobile app developer in eBay's (Nasdaq: EBAY) fold. The dot-com giant is buying Critical Path for an undisclosed sum.

Nice move. eBay knows Critical Path well, since it's the coder behind existing apps for eBay.com, StubHub, eBay Classifieds, and Shopping.com. In acquiring the smartphone specialist, eBay will make sure that it consistently cranks out updates to its programs, while also keeping Critical Path developers from working on rival applications.

5. Poetry in motion
Research In Motion (Nasdaq: RIMM) -- the Rodney Dangerfield of smartphone stocks -- may finally be getting the respect it deserves. The BlackBerry maker posted better-than-expected quarterly results last night, and issued upbeat guidance for the current quarter.

Investors may have lost faith in RIM, after it recently announced that it would no longer report certain performance metrics. It was easy to assume the worst when RIM felt that it no longer needed to discuss average selling prices, active subscriber counts, or revenue per account.

These may be trouble spots down the line, but for now, RIM is still the growth stock that nobody sees.