...text can be edited from a PSD file in Illustrator as long as no fancy effects have been used when created in Photoshop, or rasterized in photoshop before saving to PSD...
...ensure you have selected 'convert photoshop layers to objects' in the open dialogue from Illustrator, if it is not allowing you to edit the text then you will have to open it in Photoshop to make edits...
Andrew