I previously did a review of the first IE8 beta, the second one came out a few days ago so I thought it would be worth a follow up post. Here are the main things I noticed:

• Activities are now called 'Accelerators' though otherwise seem to be largely the same, so the main difference might be the renaming of the Firefox Add-on.
• Suggested sites - which looks like a less interactive StumbleUpon.
• Search suggestions - a more useful search auto-complete which looks quite cool, I've not come across any documentation on how to implement providers, however.
• 'Compatibility' mode - the IE team have followed my (ha!) suggestion and enabling IE7 compatibility no longer requires a restart of the browser, simply click a toolbar button and the page reloads. By default it will render in standards mode on the general internet and in compatibility mode on intranets. This has not been a completely popular decision, but I'm not sure why. We all knew the main argument against 'standards mode by default' is that it would break thousands of intranets, and this seems to me like a practical solution to that problem.