Sean: If you buy 3.0 for your game you will get all bugfixes to that version, but not any new releases (such as 3.5 or 4.0). This is similar to most other commercial software.
As for Erick's questions:
(1) Now that you've mentioned the advantages, are there any underlying disadvantages as well? Wink
Well, PocketHAL does not at the moment support 640x480 on the newer WinMobile 2003 SE devices if I remember correctly. Neither does GapiDraw however at the moment (it will in 3.5).
(2) Also, from what I understand, pockethal is a substitute for gx.dll right? How much work does it entail to convert a GD-gx based game to a GD-pockethal based game now?
Nothing. You simply link with a different LIB (GapiDraw 3.5 will be shipped as statically linked LIB files).
(3) Will we still be able to use GapiApplication on top of PocketHal?
Yes, in fact you will never notice that GapiDraw is using PocketHAL as a backend (except for the startup banner which can be disabled by purchasing PocketHAL from Thierry).
(4) Will you release any benchmark comparisons between a GD-gx and GD-pockethal based game?