Here's something I think is worth sharing. If you are like many GS users who were doing big orchestral projects you were using more than 1 PC. Now that you've upgraded to GS3 you may have decided to try 1 PC (due to the memory and polyphony increase) But you have all your templates split in multiple .gsp files on several PCs. Here's how to merge them into one gsp file. If you were using 2 PCs, just load one set of .gsp files (say of PC1) and save them in the new .gsi format. Then load the gsp file of the same set from PC2 and then click on the G3Port5 tab and load that newly converted gsi file and voilà! 8)
Thank you Tascam for that gsi format!