Here is the introduction for the new version:
Skype 3.0 beta for Windows Mobile integrates two big features from the desktop version--file transferring and SMS. Both are welcome additions that bring the mobile VoIP application much closer in line with the newly updated desktop version, Skype 4.0 for Windows.
The SMS feature has been seamlessly added as a shortcut icon on the contact list page (it's the black circle encasing a tiny cell phone), but you can also initiate a text message by selecting "Send SMS" from the Menu options--the cost will come out of your Skype Credit. The file transfer feature is a bit more buried. To use it, select "Contact Options" from the Menu choices, and then "Send File." This will incur a data charge, so it's best to have a data plan in place before going wild with transfers.
As soon as you ship your image, song, or document out to your buddy, a new tab opens in Skype for Windows Mobile 3.0 beta that keeps track of the transfer and lets you know when your contact has accepted the download. File transfers work both ways, of course, so you'll be able to accept files sent through Skype while you're on the go--crazy photos and important business documents included. File transfer worked without a hitch over our 3G network, as did SMS. Wi-Fi will make them even faster.
After SMS and file transferring, the next biggest change is a technical one that most people shouldn't notice--the fact that you won't have to decide between downloading the version for Windows Smartphones or for Pocket PCs. A single one-size-fits-all download makes installation blissfully brainless. In addition, the beta has undergone a few understated, but useful changes to its layout, like being able to update your status, add hyperlinks to chat messages you may have missed, and the option to buy more Skype Credit.