i think they will after some time .but to be honest not sure as we made some word changes too in one of our website witch in on 1st and 2nd page on google with ebay competitor search term .on website cache they still show old words .so now its 6th week but am sure they will soon .
It will time and some good incoming links that Google spiders Have patience my friend Remember though "nothing is for nothing' and you may have to do some "work"
I too have a 1st page website that's why i am curious and anxious to update it because lol my description was only 4 words!!
As said, with time Google will certainly notice that you updated your website. But if you want your site notice quicker, here is what you can do. If you have a blog you can install a plugin called : Google XML Sitemaps This plugin will tell Google, Yahoo, Bing and Ask.com to check your blog everytime you make a change to it. For Pinging your site, go to http://pingler.com/
I have that plug in by the way and even submitted a sitemap in my webmaster tool., so my only solution is to wait for it or Ping Google
You can find answers to your questions here: 1) Yes Google picks them up but i am not sure if Google affects your meta description for ranking results. 2) Yes. Google shows and picks it exactly as you write it.