Disclaimer: If you want to keep it as a surprise, we recommend you to not read this post, as it might spoil the surprise for you on your birthday.
In today’s Windows Live Wire blog post about the new Wave 3 web experience, we picked up something special that we didn’t cover last time when we talked about the dynamic themes in the new Windows Live headers. Here’s the hints Allison O’Mahony, lead program manager on the Windows Live Customer Experience team, gave in her blog post:

Themes - New themes allow you to customize your experience throughout Windows Live. Click Options and then click More themes to choose from twelve standard themes that apply different designs to the header. You can also choose from several dynamic themes, which change their design based on the time of day and weather conditions—some of them even offer a special birthday surprise.

Daily weather and other notifications - At the top of the home page is a new notifications area designed to help you keep on top of your day. There you’ll find today’s date and weather conditions in your location, as well as notifications of new private messages, network invitations, and the next event on your calendar. During special events such as your birthday you may see a personal message here too.

Let us show you what she meant. Of the six dynamic themes currently available, four of them – Daisy Hill, Tugboat, Robots and Sports, changes according to the weather in your location. Little did we know that these four themes gives you a nice little surprise on the day of your birthday! Here’s what the Daisy Hill one looks like, on the day of your birthday (we’ll save the other three for your birthday):

The Windows Live Home header will also greet you with a special message! And because the header is shown for the entire day without changing, the weather information is displayed as an icon instead. You can see this in the screenshot below:

To our surprise, even Windows Live Account will greet you with a special birthday message! (Sorry, my birthday is not today. But I wouldn’t mind receiving some early birthday gifts =) )

For those of you who may be concerned about others knowing your birth date, don’t worry. This special header will only appear in your own views – when others are viewing your Profile (including those in your Network), they will only see the standard header like the ones you’d see every other day. So it is made especially for you only.

Microsoft has really put some thoughts in designing the new Wave 3 theme, making it as personalised as possible, such that customers feel "special” when using their services. The Windows Live Customer Experience team have done a really good job this time, well done!