I mention the usage of HTC ExtUSB (11-pin mini-USB 2.0 and audio jack in one) in my reviews because I generally prefer to have a standard 3.5mm headset jack on my mobile phones so I can listen to music and podcasts with my own Ultimate Ears headphones. MobileCrunch questioned HTC and received a response that most HTC devices launched after the HTC Hero will have a 3.5mm headset jack. Devices already announced, like the Touch Pro2 and myDash 3G, will still have the ExtUSB port. There has been one device I know of that previously launched with a 3.5mm headset jack, the HTC Touch HD, but I think that is it. While I think the majority of people will be pleased with the strategy of using a 3.5mm headset jack moving forward, I can also see the validity of using the HTC ExtUSB port.
The problem with using a 3.5mm headset jack is that you will also need a port for syncing and charging your device. Thus you will have two cables hanging from your device as you charge and enjoy music. HTC has been including a small adapter with all recent devices that gives you 3.5mm and 2.5mm headset jack options, along with another ExtUSB port to charge/sync your HTC device at the same time as you listen to music all through a single port on the device. Also, by using the ExtUSB port HTC has been able to make devices more compact and save some space.
Then again, my standard practice is to listen to music and podcasts while I am on the train and not connect my device to sync or charge so I rarely am in the situation where I need to plug in a pair of headphones and a power cable at the same time. So, I guess I'll stick in the pro-3.5mm headset jack camp and get behind this movement. Just about every single one of the Nokia devices I use, with the exception of the E71, use a standard 3.5mm headset jack and I find I use them more often for media consumption than I do my HTC devices.