Some concern that Windows Phone 7.5 apps will not all run well on Windows Phone 8

Microsoft has not released a Windows Phone 8 SDK to all developers yet, which means there will only be a few native Windows Phone 8 apps out of the gate.

This is not however a particular problem, as Microsoft has promised Windows Phone 7.5 apps would run without any modification on Windows Phone 8.

Now LiveSide.net has however noticed that Microsoft appears to be showing less and less confidence that this promise will indeed be a reality.

Microsoft originally promised:

With regard to existing applications: today’s Windows Phone applications and games will run on the next major version of Windows Phone. Driving application compatibility is a function of Microsoft’s commitment to its developers. Regardless of what we release in terms of new developer features and functionality, we have made a large investment in protecting your existing investments.

Most recently however in a podcast, Windows Phone Product Manager Cliff Simpkins is noted as saying:

WP8 was designed to run all WP7 Apps…and where we saw that Apps that were designed for 7 could use some tweaking, whether there was performance [issues] or you know [starts to say compatibility then moves to] App and binary code compatibility might go a little bit wonky in some cases – but you get that with any release.

LiveSide have collected many quotes displaying a slipping confidence in the goal, and while it is likely the majority of apps will work without issue, it is also likely the best apps which push the envelope will be the ones that run into compatibility and performance issues.

Read more at LiveSide.net here.

Do our readers think Microsoft should have released a full emulator months ago to allow developers to test their apps? Let us know below.