Tip1: S10e now prebuilt 6-cell battery and bluetooth(so S10e need not the bluetooth set).
The "e" in Lenovo Ideapad S10e stands for education and the model is designed for the contemporary student. Therefore the S10e complement the S10 which is designed for the general consumer.

S10e vs. S10e
The S10e can be viewed as a more flexible and improved version of the S10. Here are few differances:
The S10e comes with different harddrive sizes: 4GB SSD/Flash, 80 GB or 160GB HD 5400 while the S10 is offered with 160 GB 5400 rpm.
The S10 also has a 1GB memory (PC2-5300 DDR2 SDRAM 66tMHz) which is expandable to 1.5GB and the S10e is offered with 512MB, 1GB (PC2-5300 DDR2 SDRAM 667MHz) and even 1.5GB (only with Linux).
The screen size on the S10e is a bit smaller (10.1") than the S10 (10.2")(some users dislike this), and the S10e has a WSVGA Glossy LED backlit TFT (1024 x 576) while the S10 has a WSVGA AntiGlare TFT.
Both models have Broadcom b/g WiFI wireless but Bluetooth is optional on the S10e

Tip2: how to upgrade Memory (more customer asked this question to us)?
You can choose any one laptop/notebook 667Mhz PC5300 1G or 2G memeory on S10/S10e.Because S10/S10e only has one memory on the back and Atom only support 2G memory, if you remove the 512M memory and install a 2G memory, another 512M memory on mainboard will be shielded by BIOS even you still can see 2.5G in OSX or ubuntu. Recommend 2G now!

Tip3: How to upgrade Harddisk?
You can choose any SSD 32G or 64G SATA harddisk on S10/S10e. Or traditional 80,160, 200, 250,300G 7200' 5400' laptop/notebook SATAII(Recommend WD,Seagate).

Tip4: How to upgrade to 802.11N?
You can choose MINI PCI Express Intel 5300 802.11N or Atheors AR5008, or Broadcom 4321 801.11N wifi card on S10/S10e. If there are 3 connectors on card, you can choose any wireless mini pci antenna to connect it and lay the cable under the keyboard(do not touch the mental part on mainboard).