Yahoo! may have struck gold in the hiring of Marissa Mayer as their new chief executive officer.  Experts in the business know Mayer’s capabilities: whatever project she was put on at Google, she turned it to gold.

She was the first female employee on Google and Google Executive Chairman Eric Schmidt recalled how Mayer was an asset to their company, and how she will be missed at Google.

“I worked with Marissa for many years,” he said in a statement released by Google. “She’s a great product person, very innovative and a real perfectionist who always wants the best for users. Yahoo has made a good choice and I am personally very excited to see another woman become CEO of a technology company.”

Everyone from Google only have nice words for Mayer, even Larry Page, who, according to SiliconANGLE founder John Furrier, used to date Mayer.

“Since arriving at Google just over 13 years ago as employee number 20, Marissa has been a tireless champion of our users,” said a statement from Google CEO Page. “She contributed to the development of our Search, Geo, Local and other products. We will miss her talents at Google.”

So we’ve established how lucky Yahoo is in nabbing Mayer from Google, but is Mayer just as lucky?  Is the CEO title enough to make her want to go to work everyday and face the challenges that comes with the position?

Speaking of challenges, here are just some that we think Mayer has to address in her reign as Yahoo’s new CEO.

Focus – Yahoo started as a web directory and search engine then eventually evolved into what it is today – a huge mass of uncertainty.  Previous CEOs wanted to so much for Yahoo that they lost focus–the company had so much potential but no one knew how to utilize it.  So the challenge for Mayer is, will she be able to return the company’s focus?  Or will she be sucked in in the company’s swirling mass of confusion?

Relevance –  Yahoo was so popular a few years back.  Remember when everyone you knew has a Yahoo e-mail account, uses Yahoo Messenger, and used Yahoo to search for the stuff on the interweb.  But then they started making so products and services that people started getting confused and frustrated – people started weaning off Yahoo and opted for Google’s clean, crisp look and feel.  Since Mayer was responsible for much of Google’s success, will she be able to turn things around?

Morale – if you’re an employee of Yahoo and you hear people say “Who still uses Yahoo?” That has got to put a big dent in your spirit.  With the recent Yahoo Voice password debacle, most brushed the matter off and it was even the butt of jokes in the interwebs saying that the hack was a lesson and users should no longer use Yahoo’s services.  Will Mayer be able to reinforce Yahoo’s once great reputation?

Innovation – There’s a huge focus in the mobile sector these days as companies want to make their mark in mobile devices.  Their Yahoo Mail app for Android devices is now being scrutinized by security experts as a security vulnerability in the app may have caused Android devices to send out numerous spam e-mails.  But an e-mail app is just one thing, Yahoo can bring more to mobile devices, the question now is, what can they offer that others haven’t already offered?  For one, they can do something with their ad business since that’s their most profitable sector.