 Windows Mobile 6.5 |
 Windows Mobile 6.5.3 |
 Windows Phone 7 Series |
| Windows CE kernel | 5.2 | 5.2 | 6.0 |
| Minimum resolution | None | None | WVGA |
| Skinnable | Yes | Yes | No |
| Finger friendly | No | Barely | Yes |
| Multitouch | No | Basic | Yes |
| Capacitive touchscreen | No | Yes | Yes |
| Stylus | Required | Optional | None |
| Touchscreen keyboard | Unfriendly | Finger-friendly | Finger-friendly |
| Required buttons | Start | Start | Start, Back, Search |
| Operating metaphor | Apps | Apps | Task hubs |
| Pane switching | Tabs | Swipe | "Pivot" |
| Browser | IE Mobile 6 | IE Mobile 6 | New, still IE-based |
| Zune integration | No | No | Yes |
| Xbox integration | No | No | Yes |
| Courting enterprise | Yes | Yes | Not yet |
| Social networking | Apps / Skins | Apps / Skins | Built-in |
This is a comparison of core OS functionality and differences, handset skins and carrier tweaks aren't factored in.
If you couldn't tell from the chart above, the "differences" between Windows Phone 7 Series and Windows Mobile of yore (last week) are rather hard to quantify: it's like comparing a bed with an oven. Two very different things, for two very different purposes. Windows Mobile has had a justifiable position in the realm of business, and will probably continue to maintain a legacy install base for some time to come, but it's pretty safe to say that the days of Windows Mobile as a consumer-facing OS are rapidly coming to an end. Bring on the new!