Keyword Opportunities (Beta)
The Keyword expansion feature generates keyword ideas based on words or phrases.
The Keyword multiplier combines lists of terms to form new keywords.
Data view improvements
Column auto-sizing: Double-click a column header to fit the width to its contents, or right-click the column header and select 'Auto-size Column.' To auto-size all columns at once, click the column chooser and select 'Auto-size All Columns.'
Horizontal scrolling: You can now scroll from left to right.
Column selection: The column chooser stays open until you click away or hit the Escape key.
Date picker: Use a calendar to select campaign end dates and date ranges for performance statistics.
New editing options
Copy campaign or ad group 'shells': This feature enables you to copy a campaign or ad group without the items inside, then paste the duplicate campaign or ad group into a new location. Go to the Edit menu > Copy Special.
Create duplicates when replacing or appending text: When you use the Replace Text or Append Text tools (in the Edit menu) you can now create duplicates of the items you're editing and modify the duplicates instead of the originals.
To use a separate content bid for an ad group, simply specify the bid on the Ad Groups tab. Previously, it was necessary to enable content bids for a campaign by checking a 'Content Bids' box on the Campaigns tab; this checkbox has been removed.
The upgrading your current version said to be a painless operation and you are able to do an inplace upgrade.
Follow the link the get more information and software as well.
AdWords Agency Blog: AdWords Editor 6.5