can be a number of reasons.
Normally companies get Cell phones based on BIDS.. meaning...
if HTC comes out with a WP7
one company can offer a LARGE amount of cash . and if approved by HTC can become an exclusive Phone for them.(them = Voda, orange, bell, Rogers, AT&T w/e ..ect...)
Now HTC could also offer exclusive phones or REFUSE phones to companies as well if they dont believe its worth it to them.
EXAMPLE : Nokia STOPED making CDMA phones for Bell about 5 years ago. because it cost them an extra 100$ a phone to make CDMA chips. 2 years after they stoped we launched the HSPA+ (sim card ) and NOKIA came right back to us!!! After 3 years of Not having nokia phones at Bell.
an other example is that HTC puts out a phone and tells. Orange/Vodafone ect.... its 10k to own and sell them for XX amount of time.. if they dont have the cash or if they DONT want to invest into the phone they can choose not to have it..
that why you normally see new young cell phone companies come out with CRAPY phones. its cause they dont yet have the cash to invest into better hardware..
you wana sell a phone .. you have to pay for it...
so maybe the Contract with HTC is OVER and they dint want to re-new , or they simply said SCREW wp7 ….
so all you can do is HOPE they come back with new WP7(.5)
that’s NORMALY how it works ( here in America(Canada) any ways )
hope this helps.