Website Offline after DoS Attack
WordPress 3.5 Causes Problems – Don’t Update
Be very careful before updating to WordPress 3.5, it may break vital systems. A number of plugins and themes are partly or totally incompatible with WordPress 3.5 at this time. If you have advanced features and commercial themes wait until you are certain these are fully WP3.5 compliant before upgrading, or you could lose these functions, and lose business as a result.
If you are starting a new blog or website WordPress 3.5 is fine… If your existing blog uses a default WordPress theme like TwentyEleven, TentyTwelve or TwentyTen, and only default or 3.5 proven plugins, then probably it’s OK to update. If you have extended functions on the front end, be wary, be very wary!