In my Honest opinion, it will be a "media" focus event. And some surprise have already been announced and almost confirmed...
So we can easily see:
1) New iPods: new ipod nano, new ipod touch. The iPod nano would exist in several number of colors (orange, black, white, pink, blue, green, purple, etc...). The iPod Touch would receive the iPhone 3G shape, with new firmware and maybe also the HD from the Classic... Which would have more sense to have larger size for a device you can watch movie with the large touchscreen display.
2) New iPhone / iPod Touch Firmware: New version with finally some fix bug, finally a real push (and background push), some GPS turn-y-turn and copy/paste, with some fixbugs and maybe some tiny change such MMS, delete an unique SMS in history, and maybe the "streaming audio from your iTunes" such the Simplify Media stuff and a new Apple Apps to read eBook and PDFs.
3) New iTunes 8.0: The genius list stuff with new visual effect... and maybe the integrated streaming server over network/internet.
4) New in iTunes Store: The complete song from the beatles, more content in HD (TV Shows), a special category to buy eBook, magazine, fanzine and newspaper.
Wild cards (I don't believe too much for this time):
1) Small Portable device: We can perhaps have a preview of the specific portable device for the "Book & Game" (such of iTablet, iPad, MID, etc...).
2) Enhanced version of AppleTV: We could maybe have a preview of a kind of AppleTV Pro which include also a DVR function and "streaming" function (à la Netflix / TiVO).
Unfortunately, all the computer news (new MacBook, MacBook Pro, Cinema Display, iMac, Mac Pro, Mac Mini) will be announced later during another event...
Here is my opinion on the strategy:
iPods and iPhones are really the way for Apple to have interest from non-Apple fanboys. It's the interest of Apple to be really focus and pushing really hard to have the best product to attract more people... It's a marketing Trojan Horse...
When more people will be interested about the Apple products, mostly with the interest for small/affordable large public devices, then they will release some new "sexy" product(s)... such netbook, portable tablet device, cheaper laptop/desktop, etc...
Then, a lot of people will "get it" and will be even more ready to "switch" to Mac and then consider an iMac/Mac Pro/MacBook/MBP/Mac Mini for their own and main use.
Let's see how far from the final goal we will be at this "Let's Rock" event
my 2 cents,
Spid