Verizon iPhone 4 uses world mode MDM6600 Qualcomm baseband [u]
In terms of ease of repair, the new iPhone 4 is similar to the previous version. iFixit notes that the back panel and battery are easy to replace (once you obtain the requisite pentalobe screwdriver, something the site offers as part of an inexpensive repair kit), and that the internals are all fastened with "(lots of) screws and not tabs or adhesive."
However, exchanging the front panel is "is time consuming as you must remove all components from the phone in the process." Also, because iPhone 4 fuses its LCD display and front glass panel together to improve the look of the display, replacing a cracked glass front is more expensive.
A world mode iPhone 5?
Subsequent versions of the iPhone and iPad could conceivably use the same Qualcomm MDM6600 chip to deliver world mode versions, but existing data indicates that iPad 2 will still ship in separate CDMA and UMTS versions (in addition to a WiFi-only model).
It's not yet known if Apple will opt to pack both CDMA antennas and GSM/UMTS antennas into the expected iPhone 5 this summer, or continue to sell two distinct versions. It was originally expected that the company would seek to consolidate its offerings to one model, but the design of iPhone 4 and the expectations surrounding iPad 2 suggest otherwise.
There may be fewer advantages in a single global model than in selling two separate iPhones for the time being, as a two-model strategy may allow Apple to build both versions at lower cost. Using the same chip in both would at least simplify and consolidate the development expenses in building two different models.
There is also limited demand for Verizon CDMA phones capable of roaming globally; very few models currently can, and they sacrifice size or other features to offer this.
4G iPhone 5
Interestingly, the MDM6600 chip also supports HSPA+, boosting the potential for iPhone 5 above today's 7.2Mbps download and 5.76Mbps upload HSPA speeds of iPhone 4 by adding the capability to access HSPA+ networks with downloads up to 14.4Mbps.
This would allow AT&T to market iPhone 5, using the same chip paired with GSM/UMTS antennas, as a "4G" phone, alongside other HSPA+ models now in the pipeline, including the Android-based Motorola Atrix and HTC Inspire. AT&T hasn't yet started talking about a potential "4G" iPhone because Apple hasn't exposed its future roadmap yet.
It appears less likely that Apple will add an LTE option on iPhone 5 and iPad 2, potentially giving AT&T an exclusive opportunity to market the next iPhone 5 as "4G" while Verizon continues to sell a 3G CDMA version. However, promises surrounding easy upgradability of some existing Verizon devices to LTE may also enable Apple to release a 4G upgrade module for future iPad models, and possibly even future iPhones (but not today's iPhone 4).
AT&T began marketing HSPA+ as "4G" to counter marketing claims by Sprint's WiMAX, Verizon's transitional LTE, and T-Mobile's own HSPA+ network. Previously, all of these networks were considered "3.5G" or "transitional 4G" networks because they do not meet the actual 3GPP definition of 4G mobile networks, which sets a baseline of 100Mbps downloads.