In addition to the two western Canadian territories being merged as one in the Second edition of Pacific, as Wittmann noted, they are incorrectly given a British roundel rather than the original Canadian one. The Avalon Hill website FAQ acknowledges that this is a mistake.
In terms of the sculpts, there are other differences in the second edition besides the addition of Italian-specific designs. All the countries (except China) gain an anti-aircraft sculpt (which wasn’t a unit in the first edition), and there are several new nation-specific designs that were represented in the first edition by foreign equipment: for example, the new Russian transport ship. The AAA unit that’s missing from the 1st ed of Europe won’t be a problem for the US and the UK if you have the 2nd ed of Pacific (because the two nations are in both games), nor for ANZAC and Japan (which are in the Pacific game only), but it would be a bit of a problem for Russia, Germany, Italy and France (which are in the Europe game only). You could compensate for this by buying some AAA pieces from HBG…but if you’re going to be spending extra money to fill this gap, you may not end up much further ahead than in you simply get the 2nd ed of Europe in the first place.
The 2nd ed also has upgraded poker chips – the new model with larger ridges and the A&A logo stamped in the middle.